I uninstalled the Beta 4.1, and now my firefox Beta 4.2 and 3.6 has lost all it's preferences. Is it all lost, or can I get them back?
I recently installed the 4.0b2. After that I uninstalled 4.0b1. I have now lost all my preferences (bookmarks+history+themes+ext. etc.). Is it all lost or can I get them back?
Did you select to remove your personal data while uninstalling that 4.0 b1 version?
If you select that option then all Firefox profiles will be removed, so be careful with that choice.
If you removed your personal data then try an undelete program like Recuva.