Hi Mose123654,
Sorry you are having problems with crashes. Reinstalling an older version of Firefox rarely helps.

First of all back up your Firefox profile. That has bookmarks passwords and settings in it and needs to be preserved.

• Back up and restore information in Firefox profiles

Try to run Firefox in safe mode, it may prevent crashes or at least allow a crash report to be submitted

• Diagnose Firefox issues using Troubleshoot Mode

If you are able to obtain and post a CrashID from a couple of very recent submitted crash reports it would help. It may be possible to find and submit these even when Firefox is not running please see

• Troubleshoot Firefox crashes (closing or quitting unexpectedly)

If you are unable to get links to Crash Report IDs try a reinstall of Firefox, but do a clean install involving deleting the program files. (Please make sure you delete program files and not the profile files, and back up the profile first)

• see Uninstall Firefox from your computer

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

• http://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode
• http://windows.microsoft.com/en-US/windows-vista/Advanced-startup-options-including-safe-mode

A clean install solved the problem--important to manually delete all of the old files first-reboot and then re-install

Glad to have helped. Thanks for posting back.

We have to be careful when suggesting deleting program files, it can be tricky and not the safest of things to attempt, so it is not promoted as an initial solution.