See http://kb.mozillazine.org/Software_Update (Software Update not working properly) Remove the files in the updates and updates\0 folder: XP: C:\Documents and Settings\<user>\Local Settings\Application Data\Mozilla\Firefox\Mozilla Firefox\updates %USERPROFILE%\Local Settings\Application Data\Mozilla\Firefox\Mozilla Firefox\updates

C:\Program Files\Mozilla Firefox\updates ..... Vista/Windows7: C:\Users\<user>\AppData\Local\Mozilla\Firefox\Mozilla Firefox\updates %LOCALAPPDATA%\Mozilla\Firefox\Mozilla Firefox\updates

C:\Users\<user>\AppData\Local\VirtualStore\Program Files\Mozilla Firefox\updates --- Download a fresh copy of Firefox ( http://www.mozilla.com/firefox/all.html ) and do a reinstall of Firefox over the top of the current version. If that still causes the same problem then do a clean reinstall. You can skip the step to create a new profile, that is not necessary for this issue.

See http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_rein

Thank you, but these suggestions did not help, and do not apply to my problem.

I have neither an update nor an updates folder in either Firefox Application Data folder under Local Settings or directly under my profile.

Also, I cannot install ANY version of Firefox, so reinstalling is not an option. Each time I try, I receive a message stating:

"Your computer must be restarted to complete a previous upgrade of Firefox.  Do you want to reboot now?"

Restarting my PC as Firefox suggests does not change anything.

Thanks again!

Jim

"Application Data" in XP/Win2K and "AppData" in Vista/Windows 7 are hidden folders, use %APPDATA% in the File name field See http://kb.mozillazine.org/Show_hidden_files_and_folders

I can see all my hidden folders in Windows XP, including the Application Data folders. The update or updates folder you mention is not there.

Please note: I manually downloaded the 3.6.4 installation file before installing it.

Today I downloaded Firexfox 3.6.6, and was able to install it over the previous installation. I did not try installing Firefox 3.6.4 or 3.6.3 again today, so I am not sure if this issue was corrected in 3.6.6, or if the issue just resolved itself somehow.

In any case, I appreciate the assistance. Thank you.

Jim

I had this problem updating from Firefox 3.6.x to 4 on a box running windows xp. I could not even uninstall Firefox, it kept asking for a reboot. The way I got around this problem was to delete/rename a file called "firefox.exe.moz-upgrade" in the Firefox installation directory "C:\Program Files\Mozilla Firefox". After that I was able to run the Firefox 4 installer again and things worked fine.

I had the same problem as roozta: renamed "firefox.exe.moz-upgrade" and ran the installer again, as suggested. Restarted the PC, now Mozilla doesn't start as well, but don't ask to restart the computer any more.... any more suggestion?

Pacca, Not sure if this will work or if you have already tried, but you might want to try uninstalling, reboot and then install again and see if that works.