Hi I have a problem. FireFox on both my laptop and my stationary comp triggers a BSOD instantly when started. The stationary runs Windows 7 Ultimate RTM 64-bit and the laptop Windows 7 Pro Retail 32-bit, both from MSDNAA. BSOD: BAD_POOL_HEADER Firefox version is 3.5.2 I think. Atleast on the laptop FireFox runs fine on XP. I have Reinstalled FireFox (not saving anything, clean version) to no avail. Since it's the same exact Blue screen on both machines I'm ruling out any hardware-problem. Yesterday everything worked flawlessly on both computers. 7 hours ago FireFox stopped working on my laptop. It still worked on my stationary until 90 mins ago when I rebooted it and it started there too. I've searched all harddrives on the laptop with Macbytes' MalwareBytes, SpyBot Search & Destroy and Avast! anti-virus with no results. My guess is that some update to FireFox/Windows 7 all of a sudden made this happen, which came into effect when I rebooted. Anti Virus: I had the free version of Avas! on both comps but changed to Comodo free version to check if it was Avast doing it but it wasn't. Event Viewer: No critical errors, 341 information and some warnings but not related. Other versions: I've tried out Minefield with the exact same results. IE, Opera, and Safari all work. The shortcuts to FireFox/Minefield turns to white once they've coused a BlueScreen. Anyone else have this? How could I solve it?