Error: “LU1875 This update failed during its preprocessing welcome text phase”‘

April 11, 2006
  1. Unregiter and Re-register Navlucbk.dll (C:\Program Files\Nortan Antivirus\Navlucbk.dll)
  2. Perform a disk Cleanup
  3. Restart the Computer
  4. Run liveupdate again

159 Responses to “Error: “LU1875 This update failed during its preprocessing welcome text phase”‘”

  1. Forrest Shields Says:

    Thanks for the post. You are a lifesaver!
    I found hundreds of other people who have complained about this error in online posts. Not a single one was able to offer a solution…until I read your post.

  2. John Says:

    Thanks – you seem to be the only person who knows how to fix this – saved me hours of hacking about


  3. Brendan Says:

    I’ve been trying to figure this one out for days. Wow, big time help. Let me know if I can ever help you out with a wordpress question.

  4. Stephen Oh Says:

    You are The Man !!

    Thanks for the fix – worked like a charm

  5. Tami Higa Says:

    I’m still lost. How do I register and re-register Navlucbk.dll ?
    I’ve located it but what exactly do I need to do?

  6. Xine Says:

    How do I register and re-register Navlucbk.dll

  7. Jaspal Says:

    You can register a DLL file with the following command

    # click Start > Run.
    # In the Run dialog box, type

    regsvr32 “PATH of the DLL file” (use browse to locate the file)

    To unregister a DLL file

    # click Start > Run.
    # In the Run dialog box, type

    regsvr32 /u “PATH of the DLL file” (use browse to locate the file)

    Thanks a Million Folks ๐Ÿ™‚

  8. Tami Higa Says:

    I think that did the trick! Thank you very much!

  9. StevenM Says:

    Wow , finally someone who is not repeating the same old thing.
    WORKED PERFECTLY — Someone give this person a big cookie

  10. Mark Says:

    Thanks Mate. It works you have no idea how long i have been trying to fix this problem you are truly a COMPUTER GOD who walks among us

  11. Phil Says:

    When I try the unregister/re-register process using “regsvr32”, I get a message saying that the process failed – returns an code of 0x80004005. So this fix does not work. Any ideas how to deal with this?

  12. SusanJW Says:

    I argued with tech support at Symantec yesterday about this issue. Bottom line, they are blocking virus definitions from being updated so that I will HAVE to upgrade, in my opinion, which is illegal. They sold me a years subscription, but I only got 3 months worth. Now I have to buy an upgrade or a fix for the error they created. Sure they offer a 2 for one year deal, but it’s the principle! I am so mad I want to get a class action suit.

  13. Andy Says:

    Very nice fix for a very irritating problem!! thanks!

    I work in IT support and have fixed this issue literally about 10 times at different sites.. i have always in the past used system restore to restore back to before the 6th of march (which is when this problem was introduced) – but symantec in their wisdom tell you to turn off system restore to fix it (a conspiricy if you ask me as that was only way i knew how to fix it)….

    so when i went to fix this problem and someone had turned off system restore, i was stumped and this is the only method ive found anywhere to fix it… many thanks!

  14. Jackie Says:

    Can’t believe it worked! I have fought this dumb error since 4-4-06 when definitions would not update anymore. GOOD-BYE LU1875. Hey Symantec — you need to take down your fixes and publish this one!

  15. Sergio Petrucci Says:

    Shame on thee Norton… and thanks a million folks.

  16. Vlad Says:

    yeah it worked… awesome

  17. Scott Says:

    I thought this fix worked as I was able to go through the Live Update process without getting the LU1875 error message. But… the Virus Definitions date remains unchanged and outdated. It appears that either the new definitions didn’t actually get installed, or the Virus Definitions date in the Status section does not register the new file.

  18. Jaspal Says:

    Try the Following Scott

    # Download Intelligent Updater from the following website (#10)

    # make sure that system date and time is correct

    # remove virus definitions and run liveupdate

    hope this might help u to resolve the issue. Cheers ๐Ÿ˜‰

  19. Kresh Says:

    Worked like a charm, sure makes Symantec look greedy and lame all at once, not a single fix they’ve posted has worked for me, just this one, and i got lucky on a google search to find this heh. Thanks a million

  20. Eleanor Says:

    Brilliant, brilliant, brilliant… I have been banging my head off the wall for six weeks trying to fix this. Worse, we live in a remote place with only a VERY slow connection land-line, so when the bursar sees the phone bill for the hours I’ve spent trying to fix up this stupid thing, she’s not gonna be too happy… So glad I found you! Be blessed!

  21. anthony Says:

    I am trying to RUN the Un-register and register with “C:\Program Files\Norton AntiVirus\NAVLUCBK.DLL” file but I keep getting error ” you are attempting to open a file of type application extension” -The files are used by various prgrams, modifying could damage your system.

    What am I doing wrong?? Do I have the right file?? I just renewed Norton’s recently, why don;t they help me?? They told me I have old version and that they can’t support me? Don’t get it cause I did renew, just get htis stupid LU1875 error when running, and if I don’t run it keeps popping up to run LIVE UPDATE…Please help!!

    Thank you

  22. jaspal Says:

    Hi anthony,

    I think you are not using regsvr32 before โ€œC:\Program Files\Norton AntiVirus\NAVLUCBK.DLLโ€. you should either get the msg failed or succeeded, otherwise there is a problem with your command.

    yes symantec doesnt provide phone support for 2004 or earlier versions of norton software. I would recommend you to get the refund of renewal and invest the same money for an upgrade and that would be 2006


  23. Harpreet Says:

    nagi u r god

  24. g Says:

    What can I say….
    …top posts. Had this problems for ages and now all is well again.
    Bloody symantec should be digusted with themselves.
    My registration runs out in 2 months and will NOT be renewed.
    AVG is the future and its FREE

  25. JB Says:

    Symantec was useless! This info was awesome!!! ๐Ÿ™‚
    Many many thanks.

  26. Henry Says:

    Hi folks. I was excited to find this thread, although a bit disappointed when I tried the fix and got the following response. Load library (“c:\program) failed – the specified module could not be found. I have Norton Internet Security. This is what I entered after finding the path to the file. regsvr32 /u โ€œc:\Program Files\Norton Internet Security\Norton AntiVirus\NAVLUCBK.DLLโ€
    Any help would greatly be appreciated thanks!

  27. Jason Says:

    First I would like to say that this is a great thread it helped when symantec couldn’t.

    Henry try searching for the Navlucbk.DLL file the exact location may vary depending on your version it might be able to use one of these two to find it. regsvr32 /u “c:\program files\norton systemworks\norton antivirus\navlucbk.dll” or regsvr32 /u “c:\program files\norton antivirus\navlucbk.dll”

  28. Mark Says:

    Had problems for a long time with this. Tried unregistering and registering with no luck. Jasons reply regarding a search for the Navlucbk file worked a treat as it had a different path on my computer.
    Works a treat now

  29. Kathi Says:

    Like most everyone here, I’m fustrated with the Symantec runaround! JASPAL, thanks! Your instructions to register and unregister were great!
    Thank you again!

  30. Jen Says:

    JASPAL what a life saver. This fix took less than five minutes. Short of upgrading we exhausted Symantec’s options before finding yours. Too bad for me I didn’t start here you would have saved me 2 hours. Thanks again.

  31. Peter Says:

    I echo everybody elses sincere thanks for the great advice on here!

    Symantec have published 3 or 4 different ‘fixes’ for this so far without success. The latest registers the Navlucbk.dll file but without the vital un-register step.

    However, for me, although I can now run live update successfully (without the error message) the virus definitions is still showing as being out of date. Any ideas?

  32. Henry Says:

    Yeah! Ok, I finally got it to work, the problem was on my end. I had copied Jaspal’s text at the top of this document but somehow the quotation marks were different from what my system wanted. Very strange, anyway I changed the quote marks to normal, and it worked as advertised. Thank you SO much JASPAL. A real life-saver. I also agree, this is a conspiracy by Symantec to make money. When I called them with the problem, they had me to an online virus scan. It found no viruses but one small, meaningless file at risk. They said, I had to pay them $65 to remove this file and then the problem would be fixed. Ya right. I removed the file myself, and, of course the problem remained. I am switching to AVG when the subscription runs out. THANKS A MILLION once again!

  33. George Says:

    Jaspal, when you anwered Scott’s question about the definitions date, you said to remove the virus definitions, how do I do this??

  34. anthony Says:

    thank you for help Jaspal!!!
    I was missing the something the 1st time!!
    thank again!

  35. Eric Says:

    Just found this thread; great stuff ! I’m getting the 0ร—80004005 problem Phil posted on the 7May. How did you deal with it Phil ?

  36. voeisme Says:

    I have been trying to get rid of this problem for months. Finally thought I was making some headway with Trojan.Abwiz removal tool, but in the end, it didn’t help. Tried other steps as well and can never complete all the steps. Tried your way today but once I have located the navlucbk.dll with search am unable to unregister. Library not recognizing file. When I manually go searching for it, I can’t find it either. I am no wiz, but this obsession is killing me, any advice for a dummy?

  37. You guys are the best !!! When I called Symantec “support” and Abdul answered, I kinda knew I was not going to get the answer I needed (thanks, Abdul, but u were no help). Seems like Symantec has gone the way most Corporations go when they become the darlings of Wall Street. Us little guys out here that are paying their executives exorbitant salaries are no longer viewed as “valued customers” but rather, the ignorant sheeple that support them. Makes you wonder who is acually launching these “viruses” anyway. I know firsthand of a large glass company that got caught sending out their boys to smash business windows late at night. Hmmmmmmmm!!!!

  38. CLM Says:

    Thank You!!! You are a star! Symantec should be ashamed of themselves! My mother-in-law dutifully upgraded as Symantec required and still couldn’t get rid of the dreaded LU1875 message. Of course Symantec was of no help.

    You are the knight in shing armor!

  39. Rose Says:

    Wonderful !! I’ve had this problem for weeks and tried doing the various suggestions by Symantec which didn’t work. I noticed that they have changed their website with the fix to register navlucbk.dll – which I tried and didn’t work either.

    I followed these instructions and it worked. So the unregister and/or disc cleanup is necessary to fix this problem.

    Many thanks…

  40. Ian Says:

    Great fix. Thanks.
    Only one problem after completing the fix, and this may not be related, but every time I restart my PC, I’m finding that “Auto Protect” is disabled. I have checked the “Enable Auto Protect” box under “Options” tab, clicked OK. But when I restart the computer, the box is unchecked.
    Any idea what’s causing this?

  41. Allan Says:

    Can’t seem to get this to work, I’ve tried changing the quotation marks as instructed. Really tired of getting Butt F—ed by Norton.
    Any help would be really appreciated. Thx ๐Ÿ™‚

  42. Allan Says:

    Jaspal you r a god among mortal men…..plz disregsrd last post ,apparently my pathing was worded a little differently .Once I figured that out ,your fix worked like a charm.
    Again, thx or your help ๐Ÿ™‚

  43. Rastus Says:

    You rock! Thanks!

  44. Ben Says:

    It works!
    Thank you Jaspal.

  45. Alejandra Says:

    Hello Jaspal,

    I am not the most computer literate person, My greatest accomplishement this year is is the Ipod.

    My situation is that I have tried your steps. When I get to the “run” dialog box and type regsvr32 โ€œPATH of the DLL” I get Load library “Path” failed the Specified Module could not be found”. Do you have any suggestion?



  46. Barry O'Hagan Says:

    Thanks mate,

    I have been battling with this for months but none of Symantec’s suggestions worked. Their current suggestion is basically the same as yours except they omit the bit about first unregistering the dll.

    Because they no longer support the 2004 version you can’t even contact them to tell them to update their solution. I’ll be switching to Zone Labs when my subscription runs out.

    As for Alejandra above, I think they are typing in “path of the DLL” literally instead of the actual path such as “c:\program files\norton antivirus\navlucbk.dll”


  47. Tim Says:

    As Rose on May 31 said, I agree Symantec only registered product. One needs to unregister first. You are truly a computer godsend Jaspal. Thank you Thank you Thank you!!

  48. Eric Says:

    I still can’t get this to work ! When I try the unregister process using โ€œregsvr32โ€ณ, I get a message saying that the process failed – returns an code of 0ร—80004005. Any ideas how I can deal with this ?

  49. Jaspal Says:

    Eric if you are getting an error msg code of 0ร—80004005 while registering the file most probably the file is corrupt so would recommend to reinstall software and make sure to delete the folder that has that file(navlucbk.dll) installed. That should fix the issue.


  50. Donna Says:

    How do you unregister and rerigester? I have tried all of the fixes and none of them work. I keep getting a second error that the download has a corrupt file, retry the download.

  51. Donna Says:


    I type in: regsvr32″C:\Program Files\Norton AntiVirus\NAVLUCBK.DLLโ€

    When I click OK, I get the error “Load library failed. The specified module could not be found.”

    I know I must be doing something wrong if this is working for everyone else… HELP. ๐Ÿ™‚

  52. Jaspal Says:

    Hi Donna

    You have typed in wrong command. After regsvr32 there should be a space then /u then another space followed by “C:\Program Files\Norton AntiVirus\NAVLUCBK.dll” – so the final command should look like this :

    regsvr32 /u “C:\Program Files\Norton AntiVirus\NAVLUCBK.dll”

    This will unregister the file and to register the file back remove /u but make sure that you leave the space after regsvr32.

    Better then typing the path
    > use the browse button on the run box and find navlucbk.dll file.
    > Also make sure that when you browse for that file “files of type” in the browse window should be set to “all files” – by default it would show “programs”

    NOTE : The path would differ if your using Nortor Internet security : “C:\Program Files\Norton Internet Security\Norton AntiVirus\NAVLUCBK.dll”

    Hope this will help


  53. Karen Says:

    I have read all posts in this thread. I have tried to follow the directions given to solve the problem with LU1875. I know by this time, you’re probably tired of people asking, but for those computer dummies like me, would you please list (in very plain language for dummies) how to solve this headache of a problem created by Norton Antivirus. Thanks in advance for your reply.:)

  54. LA Says:

    thank you so much!!

    I just want to mention that I DID renew and I still had this problem.

    So it may be a matter of bad programming on their part, perhaps in addition to the greed factor.

  55. Nik Says:

    I just wanted to say THANK YOU! For months I have been tryiing to fix this problem. I used the (#10) web link and it worked! Yeah no more error everyday. Appreciate it very much!

  56. Eric Says:

    Jaspel – thanks fof the tip. I couldn’t delete the folder – so I finished up unistalling and reinstalling. It’s working fine now. Many thanks.

  57. arlo Says:

    looking for information and found it at this great site.

  58. Francesca Says:

    Hi All

    I have the same problem as everyone else it seems, except everytime I browse for the Dll (thingy) cos I am hopeless it takes me to a box with drop down options for selecting a file.

    I am like Karen I need actual step by step instructions, if someone would be so kind………please

  59. Julie Says:

    I’ve been messing with this for several weeks and this worked great! Thanks for saving me time and frustration

  60. Harry Says:

    Are all these instructions that you’re telling us to perform in DOS program? Coz I can’t, for the life of me, tell whether they are or not. I found the file using “search” but that’s as far as I can get…HELP

  61. Alexis Says:

    I also need step by step instructions…the “run” step will not work on my computer and I am too old to be a “whiz” and I read all these comments but understood little.
    Is there any additional or more explicit help. I cannot call anyone cuz I am on a sailboat in the Caribbean.
    This popup to update is driving me crazy.

  62. jaspal Says:


    symantec has provided step by step instructions. Check out the following page

    Thanks ๐Ÿ˜‰

  63. Al Empey Says:

    I had LU1875 failure and I went through the repair step3 to substep 22 were it said to resart the computer. I got this far and when I restarted the computer I cannot get to step 4 to register a file to work with windows now. When I run update it says every thing is uptodate but the norton site comes up with a urgent repiar required.
    How do I fix this?

  64. Hello Jaspal !
    I just found your great way of fixing this eternal LU annoyance.
    It’s nice, fast and it worked perfectly. Thanks a lot ! Great job

  65. Adam Dickson Says:

    i have norton 2004 i have this problem here the LU1875 when i got to run the file to unregister the item and re-register it says it can not be succeeded with the file not found can you please help me on this one

  66. Thank you for the help!

  67. Donna Says:

    I am having the same problem where it says file not found.
    When I try to use the intelligent updater, it says my subscription has expired, even though it does not expire until Dec 2006.
    I called symantec and the guy told me to wait 24 hrs to try to install updates. Don’t know if I should believe him. He said it should work since they update every nite at midnight. Don’t know if I should attempt to uninstall and reinstall. What do ya’ll think???

  68. Mike Grayer Says:

    Many thanks, you have saved me paying for an Upgrade as sugested by Symantec even though I have 4 months subs remaining.
    Symantec have just lost a loyal long term customer and I am sure if they continue with this attitude will loose many more.
    Thanks again.

  69. Ian C Says:

    Phil and Eric,
    # Eric Says:
    May 21st, 2006 at 7:02 am

    Getting the 0ร—80004005 problem Phil posted on the 7May.

    I had this problem, very imporant to re-boot between unregistering then re-registering the .dll file.
    Worked for me.

  70. JR Says:

    OK…I’m completely lost with this. I have no idea where to find this file (regsvr32 /u “c:\program files\norton systemworks\norton antivirus\navlucbk.dll”) and how to edit it.

    Can someone help me here. I also need very plain step by step instructions like… go here…type this…hit this…

    I’ve attempted to find this file in the regedit and it’s not there. I just plain lost. Please help me get rid of this problem

    thanks in advance.

  71. Isabelle Says:

    Many Many Thanks !!! It works!
    The help provided by Symantec -step by step instructions- did not work for me, maybe because of the disk cleanup…

  72. Mary Says:

    WOW – you are the best!!! I don’t think I could have fixed this without the help of this site. Thanks a bunch and hugs to you all!

  73. Emilio Says:

    Thank U so much. I toke one look at Symantecs solution and thought F… this. Googled it and your solution came up. THANK U Jaspal!!

  74. Mike Says:

    thanks heaps . . . Its all good now

  75. Joan Says:

    Can I just echo everyone elses thanks? Have been sitting here in London trying to figure this out for about a week. Talk about an international community of help! I can now go to bed happy.

  76. Ralph C Says:

    Excellent, fixed a troublesome problem!

  77. Steve R Says:

    Thanks Jaspal

    Your fix original steps 1 – 4 works fine for me…all back to normal now. Would recommend a re-boot (and your a disk cleanup) between unregistering and then re-registering the Navlucbk.dll file. This is what worked for me.

  78. Mike K Says:

    The LU1875 message has had me stumped for a couple of months. Symantec said that they’d charge me for assistance but I didn’t bite. Thanks much for the advice on how to fix this.

  79. Julie Says:

    Your instructions fix the LU1875 problem, but my liveupdated will not work on its own, I have to go to the Symantec site and fix live update every week. Any clues how to fix this problem…I believe the other replies about Norton insisting that you upgrade.

  80. Steve R Says:

    Further to my original posting (above) all now works ok, the virus definitions can be updated again as normal. I’m running Norton System Works 2003 version of NAV, and my sub’ runs out in Dec 2006.

  81. John K Says:

    This actually fixed the Norton Systemworks 2003 problem. Thank You!

  82. Julie Says:

    Steven & John let me know if your live update, updates on its own every week.

  83. OJ Says:

    Getting the 0ร—80004005 problem can’t take much more aaaaaaagggggggggggghhhhhhhhhhhh PLEASE HELP

  84. Tre Says:

    My lil bro (18) tries to fix the error so he located the file: โ€œc:\program files\norton antivirus\navlucbk.dll” and accidently DELETED THE FILE! Than, he used Disk Cleanup and now I dont have the file anymore. After that, I restarted the computer and ran LiveUPDATE & suddenly ANOTHER problem occurs: “LU1845: This product was not updated due to a processing error.”

  85. Steve R Says:

    Hi Julie

    I don’t use the ‘automatic LiveUpdate’ feature of Norton SystemWorks (I like to have a degree of control), but when I click onto the Live Update tab and click start, it connects to Symantec, checks all installed components of SW, and updates my virus definitions (if there are any new definitions). So it completes the process as normal (again now).

    Please be aware, as others have rightly pointed out, the location of the Navlucbk.dll file could be different on your system, depending on what Norton application (that includes NAV) you are running. As you can also see from this blog, for anyone who is not sure how to unregister and re-register a dll file, it has clearly been explained by Jaspal, 8th item from the top.

  86. Julie Says:


    I followed the process that Jaspal explained and it corrected the LU1875 problem. I can click on to live update and it connects to Symantec and checks everything and says that it has updated. But it does not have the correct virus definitions. That is why I have to go to Symantec and fix it every week.

  87. Robert w Says:

    I don’t know who on earth you are Jaspal, but the second half of your name is Pal and that is what you are. A Pal

    Norton need a bullet, this problem is a shocker and real people needed a real solution not some geek speak rubbish that they gave on their web site thanks again. Hey stand up and give yourself a pat on the back

    Rob W New Zealand

  88. Roscoe Says:

    Jaspal —

    My problem is a bit different:

    1) My subscription for Norton SystemWorks 05 expired.
    2) I purchased the upgrade for 06 and renewed.
    3) I uninstalled 05, installed 06 and ran all the LU’s and such.
    4) Initially, my AV def’s show up-to-date, but when I open Outlook the definitions are said to be out of date – reverted back to a 9/21/2005 definition set.

    Any ideas?

    Thanks in advance.

    – Roscoe.

  89. Ian G - France Says:

    Great job! I don’t use win2k much now (longtime Linux fan) so somewhat surprised NAV2003 (which I use for the same reason as I use Win2k – reasonably resource-efficient & reasonably stable ) came back with this error when I had to boot my machine into Windows.

    Your fix worked fine & I’ve manually updated NAV – will check “auto” works next week.

    But if the problem really is Symantec trying to push their new products (it’s not as though we don’t *pay* for our annual subscription update) then “disgraceful” is the only word for it. If I choose to use an “old” product & accept it isn’t supported then that’s my choice; but if I pay to continue to use it then I expect it continues to update. Symantec should just be honest, discontinue the product, don’t offer the option to “renew”…and watch their customer base disappear and install AVG – which is exactly where I’m going next subscription date. AVG does what it’s supposed to, is much less resource-hungry…and there’s a free version.

    Thanks again for posting this fix.


  90. ray Says:

    I have received the โ€œError: โ€œLU1875 This update failed during its preprocessing welcome text phaseโ€โ€˜โ€
    and I have read the solution but can someone tell me how I deregister the Navluck.ddl file and reregister it

  91. Ron Says:

    Kia Ora Thanks everybody for your comments. I too got the
    LU1875 error. Symantec’s solution was to upgrade when I have just recently resubscribed. Thanks to all those who supplied the
    solution I was able to fix the problem. I too did not know how to
    unregister and reregister. Much appreciated. Thanks all.

  92. Meemee Says:

    I recently renewed an older version SystemWorks and got this same darn error message when trying to use Live Update. I went to Symantec’s site and used option #10 for the Intelligent Updater to download definitions. It seems to have worked. It took about 20 minutes.. with a dsl connection. Thanks all for the helpful contributions on this board.

  93. ray Says:

    I tried the solution and everything seems to be in order now
    many thanks for the assistance needless to say when it come to the time to top up the subscription I will be looking elsewhere

  94. Ralph Says:

    This does work however like many others who have said already on here I did not know how to register and unregister.

    Jaspals instructions are spot on however you need to know that spaces do make a difference!

    Thanks to Forrest Shields and Jaspal

    From a non-techie!

  95. Elaine Says:

    Thank you so much! I had trouble with the unregister/register bit until I hit the browse button and got the direct file path. Even though I would type it correctly with the spaces and ” it wouldn’t work. Once I did it with browse worked like a charm!

    Absolutely ridiculous that Norton did not put this at their website! Saw their directions immediately went to google and found this. Thanks again

  96. Rodney Dixon Says:

    Another satisfied customer. Thanks for the info!

  97. lowjones Says:

    Worked great…..Thanks

  98. Dale Says:

    Another Thanks here ….

  99. Jason Says:

    Thanks. That worked very well.

  100. Gary Says:

    And me too….worked like a champ.
    Much Abliged.

  101. vlad Says:

    worked for me too……people power……..thanks

  102. Markymfmark Says:

    Your the greatest, thank you so very much!

  103. Henriette Says:

    Hi all helpers,

    You are angels ! After a few failures it worked !
    Million thanks!

  104. Chris T Says:

    Yeah, well done…..worked a treat. Used the “browse” option instead of typing it out – seemed easier to do that. (Don’t forget to click on “all files” when searching for the Navlucbk.dll file, as it won’t be shown otherwise.

  105. Vampyra Says:

    Thanks to all.

    Worked great first time.

  106. Dan Says:

    Thanx For the Info Jaspal, it worked great!

    I noticed where others have had some issues with file not found or path not found etc, You must enter the quote marks via keyboard simply cutting and pasting the instructions seems to give the incorrect quote marks causing the file not to be found. Also had to use the auto updater as you suggested, again excellent advice.

  107. Brenda Says:

    Jaspal, thanks from me too! Worked perfectly.

  108. Krista Says:

    Thank you, Jaspal! I have been trying to fix this problem since I renewed my NAV 2004 in April of this year. How frustrating for all these users. I, too, will be converting to another antivirus tool when next April comes around. Thanks again for sharing the solution!

  109. Dom Says:

    Thankyou from me too. My Mum recently had this problem (NAV2004) and now mine’s just done it too (NAV2003) so I’m glad I could get it sorted quickly without reinstalling which is what I did on my Mum’s as I didn’t know about this website then.

    For some reason since this problem happened, even though it’s now fixed, the icons on the LiveUpdate screen have changed (ie. next to each of the different components that can be updated) and if I do a manual LiveUpdate it doesn’t berate me about the Autoupdate not working (which it has done for years because I’m on Service Pack 1 of WinXP)

  110. Indi Says:

    Thanks!!! Awesome info and worked fine for me on Systemworks 2003.

  111. Nik Says:

    A true genius!
    Bye bye Norton when my subscription comes up for renewal in August. It’s AVG for this boy!!

  112. Dan Says:

    Great info, much obliged.

    Just a hitch.

    De-registering was no issue.
    Re-registering is. Using the same command less the /u as per Jaspal’s instructions

    Keep coming up with failure code 0x80040154.

  113. Steve M. Says:

    People are forgetting to include the quotation marks as indicated. In other words, to UNREGISTER, type exactly as follows: regsvr32 /u “C:\Program Files\Norton Antivirus\NAVLUCBK.dll”

  114. David C. Says:

    I have also been suffering from LU1875, and despite everything people say about Symantec I found a solution on their website at

    It is the regsvr32 procedure that has been described here. The easiest way is to copy and paste the commands from the webpage into the command prompt window. The command fails a couple of times simply because the dll file is not in your setup – I expect Symantec are just covering all their different products. Live Update now seems to work OK manually.

    I still get the Scheduled Task “Symantec NetDetect” failing, though.

  115. Martin Andersen Says:

    Thanks to Google and Jaspal, fixed with no trouble.

    Symantec’s solution was fixed AFTER Jaspal posted his fix, if you follow the thread.
    And yes, the Symantec solution goes through registering/deregistering the file for 3 different products, though obviously you only have one. The only difference is the location of the file.

  116. Dan Says:

    Look, no matter what I did I could not re-register the file.

    Even following Symantecs instructions to the tee were no help.
    So I followed their “What if this didn’t work?” prompt and was directed to Symantec Auto Fix which after a few steps re-installed the Virus Definitions file.
    Problem solved.

  117. Peter Midgley Says:

    Thanks for your help. I found many useful tips in the thread.
    I fixed my copy of Norton Systemworks 2003 using, in essence, the directions now posted by Symantec (last modified 30/06/2006). I did not use Disk Cleanup. I did not use cut and paste to insert the the command. Having first established that there is only one copy of Navlucbk.dll on my system I ran regsvr32 using the Browse function to include the path and file definition. I did restart my system between each step. The process worked first time.

  118. regine Says:

    Thank you, Jaspal! worked for me when i did the spaces i had to put in between , that you mentionned above, everything is ok now..


  119. Jim Says:

    My congratulations as well and a job well done!!

    This just happened to me in the past week. Guess I was fortunate to have missed this problem for so long. And it is curious that it seems to happen to people at different times. So what triggers this change in the dll file?

    I don’t know if the following observation has anything to do with this happening or not, but I have ZoneAlarm installed on my computer and last week an executable called LuCallbackProxy.exe tried to access the internet from my computer. Naturally before I gave it permission, I Googled it and found that it belonged to Norton. Seemed odd that all of a sudden a piece of Norton would be calling out since my Norton has been installed for a long time. But, trusting Norton, I gave it permission. It was the following week that I got the message that my virus definitions were out of date in spite of the fact that I had it on automatic. Initiating an update gave me that message and Google brought me here. Which brings me to this point: The name of the dll file is navlucbk.dll and the name of the executable that tried to phone home is lucallbackproxy.exe.

    Anyone see a similarity?

  120. R Says:

    Worked… you rule.

  121. Rae-vyn Says:

    *phew* What a pain in the butt! Thank you for this site – you rock! Note – for users who followed the steps and run into issues re-registering the .dll file. Try cold-booting the system (power it down completely and then power it back on) complete the process. The same goes for if you get the “0ร—80040154” error. Also note – if may be beneficial to not be on the internet when performing this – as the modules are being called automatically to update Norton – this may interfere with the correction process. AND… don’t forget to shut the system down completely and then bring it back up. (some processes remain in memory, which may conflict with the ‘fix’) Again, thanks for this website! ~R~

  122. Wallace Says:

    Thanks! I’m temporarily the office genius. One problem I had was trying to unregister and re-register using your exact path name, even with the correct quotation marks, etc.
    I found the correct path name my using “search” and typing in NAVLUCBK.dll.
    The correct path (for my computer anyway), came up and that’s what worked.
    Thanks Again!

  123. rob Says:

    Took some time to find you. Thanks very much for a great advise. It seems to be working. Imagine you already knew that.

  124. Linda Says:

    Thanks for the info – worked great – thought I was going to have to pay to upgrade to latest version of Antivirus when I had the error message so you have saved me some money. Regards

  125. Jeff Says:

    As much as I DON’T care for Symantec, this link did me right…
    Just follow the instructions.

  126. Saxster Says:

    Thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you!!!!!!

  127. Mike Floutier Says:

    Thanks Everyone!

    I had this problem, entered the error message in a search engine, found this thread, and HEY PRESTO I’m up and running again!

    Thanks again.


  128. Phil Says:

    Thanks everyone I have got rid of LU 1875 at last using your information. It took a while as I was using lower case for the dll file. On my pc the file is in uppercase
    I never had any problems on the internet until my lad bought me Symantec a few years ago. Now I seem to spend most of my time on the net updating and sorting out problems in Symantec.
    Glad I found you.

  129. Nancy Says:

    It worked!!! THANK YOU!!!!!!!!!!!!!!!!!!!!!!!

  130. Teresa Says:

    I have done everything that you have said.I’ve done everything that Symantec has said to do on their website but I can’t get it to change. I have located the file manually by going in my โ€œC:\Program Files\Norton AntiVirus\(This file is in there) NAVLUCBK.DLLโ€ but when I run the regsvr32 /u and browse for the file it’s not showing it in Norton but whenI go manually in the folder it’s there. Does anyone have any more suggestions?
    And I still get the โ€œError: โ€œLU1875 This update failed during its preprocessing welcome text phaseโ€โ€˜โ€

  131. Marjan Says:

    Hi. I’ve tried all of the above and the error message I get is:

    No DLL name specified.
    Usage: regsvr32[/u][/s][/n][/i[:cmdline]] dllname
    /u- Unregister server
    /s- Silent; display no message boxes
    /i- Call DllInstall passing it an optional [cmdline]; when used with /u calls dll uninstall
    /n- do not call DllRegisterServer; this option must be used with /i

    Please help!

  132. Teresa Says:

    Okay, I’ve worked on mine all day, NOW I GOT IT!!
    1. Unregister Navlucbk.dll (C:\program files\norton antivirus\navlucbk.dll)

    a. Click Start > Run
    b. In the Run dialogue box type or paste:
    regsvr32 /u “c:\program files\norton antivirus\navlucbk.dll
    (include vertical quote marks as above, not slanted or curved (โ€œxโ€)

    2. Reregister Navlucbk.dll

    a. Click Start > Run
    b. In the Run dialogue box type or paste
    regsvr32 “c:\program files\norton antivirus\navlucbk.dl

    3. Perform a disk Cleanup
    4. Restart the Computer
    5. Run liveupdate again

    Let me know if this got it to work just like I did today!

  133. Princess Peach Says:

    Thank you so much, your a little star x

  134. Stan Says:

    Thanks for solving one of life’s great mysteries. After so many hours of wasted time, I was so upset. I decided to try one more place before deleting Norton and found you… certainly a genius. You did what no one else could.

    Let me add one thing for those who couldn’t make your fabulouls fix work. Like some of the others, my first attempt failed with the path C:\Program Files\Norton Antivirus\Navlucbk.dll. Then I remembered back to the DOS days of eight digit folder names and changed the path to regsvr32 /u c:\Progra~1\Norton~1\NAVLUCBK.dll. That’s all I needed and it worked like a charm.

  135. Tom Says:

    Well the Unregister-Reregister got rid of the LU1875 problem and the definitions seemed to update, but when I checked the Definitions date it didnt change, anyone experience this problem?

  136. Robin Says:

    Just a word of thanks – thank you.

    Renewed my subscription with Norton – two weeks later out of no where I started getting this problem. Contacted Symantec for help/refund, got an offer to upgrade – about as much help as a chocolate fireguard. Thankfully now sorted, but will think twice about renewing or upgrading – any recommended alternatives?

  137. Tony Says:

    I was able to update virus definitions, after the LU1875 error, by turning off “Auto-Protect” option.

  138. Nick Says:

    Thanks Tony, it woked well:)

    For those of you who try Tony’s solution, you have to dsable Autoprotect *and then restart your computer* with it sut off before you can run LiveUpdate. Otherwise it will not work.


  139. Teresa Says:

    Mine is working fine. I get updates without disabling Autoprotect
    after doing this.
    Click Start > Run
    regsvr32 /u โ€œc:\program files\norton antivirus\navlucbk.dll
    regsvr32 โ€œc:\program files\norton antivirus\navlucbk.dl
    Perform a disk Cleanup
    Restart the Computer
    Run liveupdate again

  140. Dave Burton Says:

    Thank you, Jaspal, you solved it for me, too!

  141. CArbison Says:

    I have the same problem. It occurs everytime Norton tries to update part of the program itself. I uncheck the “Turn on protection for my Symantec program” and Live Update works.

    I then turn it back on after.

  142. jbuco315 Says:

    It’s fixed!!! Had problem using regsvr32. Kept saying Module not found. Huh… Then found solution at Norton site, This fixed it and has been working great since. Thank you everyone.

  143. Andria Says:

    I have been reading all the responses to correct the LU1875 error but nothing is working for me. I run a live update and everything shows as being updated but the Symantec Shared Components. That’s when the LU1875 appears. When I try to unregister the DLL file, I get the return code 0x80004005. It says my definitions are current and I really don’t know what the shared components are. This has just started in the last month. Any advice would be appreciated!

  144. jaspal Says:

    Hello Andria,

    If your getting reture code 0ร—80004005 while registering a DLL file most likely the file is corrupt or damaged. So i would suggest to reinstall norton. you can remove norton through the removal tool symnrt which you can download from After using the tool make sure that you deleted all norton and symantec folder from the computer. check in c:\program files\, c:\program files\common files\ and c:\documents & settings\all user\application data. if you cannot find application data folder then click on the tools menu > then folder options > click on the view tab > select show all hidden files and folder > click ok.

    Then Install the software either from CD or if you have download the product install it thru the downloaded file or redownload the software

    Hope this helpz thzx

  145. Andria Says:


    I tried your suggestion but still no luck. I think I’m just going to take my chances because the only time LU1875 appears is after updating and only for Shared Components. My virus definitions always show they are current. I had just renewed my subscription on line in May and when it expires, I think I will switch to McAfee. Thanks for your help, anyway.

  146. Jaypee Says:

    how bout error LU9001? do you have any solution to it? i’ve tried Symantec’s Autofix tool but I still get the same error over and over again. there seems to be no solution to this even in Symantec’s site. If someone knows, please help. Thanks in advance! ๐Ÿ™‚

  147. prabhakaran Says:

    while update the norton antivirus i got the LU9001 error. it say to later update. wat i have to do my syatem is infected virus

  148. John Says:

    Cheers worked fine. It is worth checking when the Navlucbk.dll file is as if is in different places on different installs. Thanks people.

  149. garylboteler Says:

    please download program number 6

  150. John Says:

    Thanks! Right on. Symantec, of course, professed complete ignorance of the error code after the required hold time. Had I not renewed Norton, I would dump ’em now. Next year. The above unregister/reregister of the .dll works as stated.

  151. ass parade
    3 IcentyRorsherlornmex

  152. Andrei Says:

    Unfortunately I don’t have the Norton Antivirus folder when I go to c:\program files but instead I have the NavNT folder when I go to c:\program files and I have the Norton Antivirus Corporate Edition version 7.61.928 and I can;t get the latest virus list definitions, how can I fix this?? I was also not able to find for a file named Navlucbk.dll so how do I fix this?? Please help!!! Just e-mail me the solution please….thanks!!!

  153. grace Says:

    I have the same problem using SYMANTEC ENDPOINT PROTECTION. Since I cannot found C:\Program Files\Nortan Antivirus\Navlucbk.dll so what can I do?

    I have only Symantec folder and cannot found Navlucbk.dll.
    Please help.

  154. Teresa Says:

    Do you have in your folder options “do not show hidden folders checked under folder options? To this go under my computer and at the top left corner under tools, folder options, view, you will have to check “show hidden files and folders”. Hope this helps.

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