Updated firefox but it didn't work with certain add ons or websites I use a lot. In an attempt to undo the the upgrade I deleted FF completely. Now using IE8 when I download FF again 7.01.exe downloads (and can be saved) and the extraction appears successful. Then a dialogue box asks- run as current user or administrator. I have admin status (my own laptop) so click current user. Then the dialogue box disappears and that's it - no evidence that FF was ever there - no icons or listing in the programme menu, although .exe remains saved. FF3.6 exactly the same. Any number of iterations or reboots doesn't help. Thanks