Automatic update got hung up for over 30 minutes and had to force quit, now firefox opens but nothing functions correctly (tabs, menu, history, etc. broken).
I tried downloading Firefox again manually... from Firefox I got an error message about not being able to open the source. So, I downloaded from Chrome. This worked but Firefox loaded right up with the same problems. I would use the "Help > Troubleshooting Information" menu to reset to factory defaults, but when I click on "Troubleshooting Information" nothing happens (nothing happens when I click on anything within the menu).
Opaite Mbohovái (1)
It is possible that anti-virus software is corrupting downloaded files or is interfering otherwise.
Try to disable the real-time (live) scanning of files in your anti-virus software temporarily to see if that makes downloading work.
See:
- http://kb.mozillazine.org/Unable_to_save_or_download_files
- browser.download.manager.scanWhenDone
Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.