It's in Help -> Troubleshooting Read this article to see what it preserves (or "tries to preserve"): http://support.mozilla.org/en-US/kb/reset-firefox-easily-f

It's in Help -> Troubleshooting Read this article to see what it preserves (or "tries to preserve"): http://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems http://support.mozilla.org/en-US/kb/reset-firefox-easily-fix... FWIW, I just tried it and it indeed made things a whole lot faster.