When Firefox crashes, it usually records information about what was happening at that moment. You can submit that data to Mozilla and share it with forum volunteers to see whether it points to the solution. Please check the support article "Firefox Crashes" (especially the last section) for steps to get those crash IDs, and then post some of the recent ones here.

If Firefox will not run long enough to use the about:crashes screen, see the section about extracting the crash IDs from the file system instead.

Also, could you try yet another two-minute experiment?

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run):

firefox.exe -P

Any time you want to switch profiles, exit Firefox and return to this dialog.

You'll click the Create Profile button. I recommend using the default location suggested, and to avoid data loss, not re-using any existing folder. Then start Firefox in the new profile you created.

Is it stable? For how long?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

Two follow-ups based on your posts in other threads:

• It's still a good idea to manually disable hardware acceleration in the new profile.

• If you want to try Firefox 25.0.1, if you can load links in the new profile, try this article: Install an older version of Firefox (the link is for the previous version compared with the one you are visiting with).