Are you using Zone Alarm? If so, which version?

No I am not using Zone Alarm.

I have the same problem. firefox 3.6.6 will not install because license file cannot be found.

In that case, uninstall Firefox, reboot your computer, delete the C:\\Program Files\Mozilla Firefox\ folder, then try re-installing using the instructions at How to install Firefox on Windows

Hi Chris.

Won't I lose all my bookmark information and addon's if I do this?

Nope. That info is kept in your profile folder. See Profiles - Where Firefox stores your bookmarks, passwords and other user data

I had the same problem when updating to 3.6.6 from within Firefox. I ended up downloading the 3.6.6 complete install file separately and then running that directly from Windows. The installer detected that I simply needed an update to 3.6.6 and when all done, everything was working again. Basically, the same thing that Chris_Ilias recommend, but you might not need to delete Firefox first.

HTH

Thanks I downloaded and installed 3.6.6 separately and installed just fine

I do use zone alarm. Does it matter?

Run the Firefox program once as Administrator (right-click: Run as Administrator).

If that doesn't help then do a clean reinstall.

• Download a fresh Firefox copy from http://www.mozilla.com/firefox/all.html and save the file to the desktop.
• Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
• Don't remove personal data when uninstalling.
• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.

Your bookmarks and other profile data are stored elsewhere (not in the Firefox program folder) and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.