Clearly that should not happen, and it is probably unusual you get a BSOD instead of a firefox crash. Are you using a firefox 64 bit experimental version rather than the standard 32 bit version of firefox ? It is probably worth doing a full security scan of your system with multiple tools / software: * see [[is my firefox problem a result of malware]] * [[firefox crashes]] If you resort to doing a re-install of firefox note NOT to use any option that removes personal settings, however that is worded, because you would be likely to then loose passwords and bookmarks etc from all normally installed versions of firefox.