How do I fix the problem I am having with Norton AntiVirus? The error is Nmain caused an error in NMAIN.EXE.

When I try to start Norton Antivirus, I get the following error:

"Nmain has caused an error in NMAIN.EXE

NMain will now close.

In addition, the following appears:

Unhandled exception has occurred. The error was "Unknown (0XC0000005)

Please let me know if you can help.

Thank you

This question was answered on September 16, 2003. Much of the information contained herein may have changed since posting.

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Situation:

You are using Windows Me and Norton AntiVirus (NAV) You downloaded and installed the Microsoft virtual machine update from http://windowsupdate.microsoft.com When you restart the computer, you see the message "Norton AntiVirus has detected the virus Xmldso.cab in c:\windows\java\classes\xmldso.cab."

You chose to quarantine or delete the file The next time that you attempt to start the Norton AntiVirus (or Norton SystemWorks) program interface, you see the error message "Nmain caused an error in Nmain.exe" or "Nmain caused an invalid page fault in Nmain.exe."

This error can also occur if your computer has been infected by the W32.Goner.A@mm worm or one of the W32.Klez worm variants.

Solution:

This has been reported in the following situations:

The computer has been infected by one of the W32.Klez worm variants

The computer has been infected by the W32.Goner.A@mm worm

When using the retail version of NAV 2000 under Windows Me This configuration is not supported as the retail version of NAV 2000 is not designed to operate under Windows Me

When using the OEM version of NAV 2000/2001 that came preinstalled on a computer running Windows Me Technical support for OEM versions of NAV is provided by the computer manufacturer, and not by Symantec Please contact the computer manufacturer's technical support for assistance with this problem For additional information on the OEM version of NAV 2000 for Windows Me, see the document Norton AntiVirus 2000 and Microsoft Windows Millennium Edition compatibility.

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Note: The OEM version of NAV 2000 for Windows Me is version number 6.20.04

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To determine your version of Norton AntiVirus

Click Start, point to Find or Search, and then click Files or Folders

Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked

In the "Named" or "Search for..." box, type--or copy and paste--the following file name:

navapw32

Click Find Now or Search Now

Right-click Navapw32.exe, and then click Properties

Click the Version tab to display your version of NAV.

To determine whether your computer has been infected by one of the W32.Klez worm variants

If your computer is infected by of the W32.Klez worm variants, then that worm has damaged some NAV program files To restore the functionality of NAV, you must run the W32.Klez removal tool to remove the worm If the removal tool detects the worm, then follow the instructions in the W32.Klez Removal Tool write-up to remove the infected files When the worm is removed, follow the steps in the document How to restore Norton AntiVirus after removing a virus to uninstall and reinstall NAV, update the virus definitions, and then run a virus scan to make sure the worm has been completely removed.

If the removal tool does not detect one of the W32.Klez variants, then run LiveUpdate and download the latest virus definitions and then follow the steps in the document How to configure Norton AntiVirus to scan all files to configure NAV to scan all files Then run a full system scan.

To determine whether your computer has been infected by the W32.Goner.A@mm worm

If your computer is infected by the W32.Goner.A@mm worm, then that worm has removed some NAV program files To restore the functionality of NAV, you must uninstall NAV from the Add/Remove Applet in Control panel, restart the computer, and then run the Rnav.exe removal utility to ensure that all of the NAV program files have been removed, and then reinstall NAV Follow these steps in the order listed:

Uninstall NAV by following the instructions in How to uninstall Norton AntiVirus

Restart the computer and then download and run the Rnav.exe removal utility by following the instructions in the document How to uninstall Norton AntiVirus using the Rnav.exe removal utility

Restart the computer, and then reinstall NAV

Restart the computer at the end of the installation process, and then run LiveUpdate to download any available program updates and the latest virus definitions If you download program updates, then restart the computer when prompted.

In the other two situations, it is not known at this time why this problem occurs Even if you can get past the error message, when you open the NAV program interface, then it is unlikely that you can successfully restore the file from quarantine.

In most cases this problem can be fixed fairly easily by using Windows Explorer to delete the .cab files from the \Program Files\Norton AntiVirus\Quarantine folder See "Solution 1." If this does not fix the problem, then you must follow the instructions in "Solution 2."

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Note: Once the problem is fixed, before you download the Windows update again (if necessary), we suggest that you temporarily disable Auto-Protect before installing the update.

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Solution 1

To delete the .cab files from the \Quarantine folder:

Start Windows Explorer

Make sure that Windows is configured to show file extensions To do so:

Click the Tools menu, and then click Folder options

Click the View tab

Uncheck "Hide file extensions for known file types."

Uncheck "Hide protected operating system files" and under the "Hidden files" folder, click "Show hidden files and folders."

Click Yes at the Warning dialog box

Click Apply, and then click OK.

Browse to and open the C:\Program Files\Norton AntiVirus\Quarantine folder (If you have Norton AntiVirus installed to a different location, then make the appropriate substitution.)

In the right pane, select any .cab files that are displayed They will look similar to the following:

For each one, press the Delete key, and then click Yes to confirm

Ensure that Windows is configured to hide file extensions To do so:

Click the Tools menu, and then click Folder options

Click the View tab

Check "Hide file extensions for known file types."

Check "Hide protected operating system files" and under the "Hidden files" folder, check "Do not show hidden files and folders."

Click Apply, and then click OK.

Close Windows Explorer, and then start NAV

If this did not fix the problem, then proceed to the next section.

Solution 2

Follow these instructions only if the Solution 1 did not solve the problem What you need to do depends on your version of NAV.

OEM version of NAV 2000/2001

If you are using the OEM version of NAV 2000 that came preinstalled on a computer running Windows Me, then do one of the following:

Reinstall the OEM version of NAV 2000/2001: Please contact the computer manufacturer's technical support for information on how to do this Before doing so, however, reapply the Microsoft virtual machine update (You may need to download it again.) If you have any problems reinstalling NAV, then you may need to manually uninstall it For instructions on how to do this, see the document How to manually uninstall Norton AntiVirus 2000 for Windows 95/98

Upgrade to NAV 2002: NAV 2002 includes new features and enhancements, such as SmartScan, Automatic LiveUpdate, and improved usability For more information, go to the following Internet address:

http://www.symantec.com/nav/nav_9xnt/

Retail version of NAV 2000

If you are using the retail version of NAV 2000 installed on a computer running Windows Me, then this configuration is not supported as the retail version of NAV 2000 is not designed to operate under Windows Me Norton AntiVirus 2002 includes new features and enhancements, such as SmartScan, Automatic LiveUpdate, and improved usability For more information, go to the following Internet address:

http://www.symantec.com/nav/nav_9xnt/

About the author

Posted by Susan of Mesa Community College on September 16, 2003

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