Did you try sending a crash report, and did you follow up by trying to get crash IDs & crash signatures ?

Firefox 6 may have a problem with malware, a particular Trojan is known to be able to crash it. If you suspect a malware problem do a full scan with security software, say which software and version you have used. MS do I believe normally provide free software capable of detecting such problems.

Currently the top specific reason for crashes of Firefox 6 is use of software involving IDvault, a particular component of that can crash Firefox, the develpers of that software are aware of the problem and working on a fix. Do you use IDvault ? if so it may be worth considering disabling it or uninstalling it. (I believe it is sometimes supplied by Comcast).

Thanks for helping me out on this. I just did full scan with Malwarebytes Anti-Malware 1.51.2.1300. It didn't find any infected object. Also, I don't use IDvault. I did file a crash report but don't know how to get crash IDs or signatures. Any other suggestions?

Sorry my quick reply was not as helpful as it could have been. It is probably a good idea to try firefox in Firefox's (Not MS))safe mode, but do not make changes when you get the first dialogue with a list of options, just click on continue.

Safe mode does not disable plugins, so it is also worth trying disabling plugins. See troubleshooting plugins. The basic unmodifed Firefox should be stable and not crash. Firefox certainly works on my own XPs without crashing.

The crash IDs are seen as links if you type into the location bar about:crashes clicking on those links should then generate a crash signature if you are lucky.

• see firefox crashes
• if firefox is crashing before you can do that then try to access the info from the OS see http://kb.mozillazine.org/Breakpad#Using_the_file_system_to_vi...

If you are re-installing Firefox, then if this is because the original install is thought to be the cause of the crash, then it is worth deleting the original files so that you get a clean install. (But do NOT delete the profile files, they have your settings bookmarks etc, and do NOT use any remove personal data options - however it is worded)

• for detailed instructions see http://kb.mozillazine.org/Standard_diagnostic_%28Firefox%29#Clean_reinstall

This sounds like the way to go, but I can't figure out how to follow the instructions (below) for starting in the safe. I'm stumped by "At the top of the Firefox window'" because I can't open the Firefox window before it crashes. And the instruction about holding down the Shift key while staring Firefox also doesn't work. Thanks again!

How to start Firefox in Safe Mode At the top of the Firefox window, click the Firefox button, go over to the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog. For Windows XP, click the Help menu and select Restart with Add-ons Disabled.... Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.

You may find holding down the shift key whilst clicking on an icon shortcut or listing works, if not then use the commandline method. Also note a standard Firefox install on XP probably even includes safe-mode as an option if you look in

• Start -> All programs -> Mozilla Firefox ->

You can probably type in firefox.exe without including the full path, but if that fails work out and include the full path. You probably also need to be careful about where to include spaces and inverted comas. (Start with the opening inverted comas and place the closing inverted comas immediately after ...firefox.exe follow that with the command-line argument so " ... firefox.exe" -safe-mode)

• see also http://kb.mozillazine.org/Command_line_arguments

If you want to follow the instructions you are quoting, note it appears to expect you to have the (orange) Firefox button, you may also first of all press the Alt key on your keyboard that should display the menubar, and the old style help menu, then the restart option should be seen when you click on help.