Its more likely to be one of the October updates from microsoft. I had this exact same problem after I installed the October updates and only got rid of it when I did a complete reformat and re-instal minus any of the updates after September. I tried everything I know to narrow it down to which of the 10 or so updates I installed that month, but couldn't figure it out. I tried sifting the memory dumps after the crashes but couldn't pin it down to anything specific because it was happening with a variety of different drivers, though one of the Nvidia drivers was a more regular cause (though when I got rid of it, I still had crashes, just less frequently). I was getting 5 - 10 crashes a day where my system had been really stable prior to the updates (I can't remember having had a crash in a couple of years prior to that). I tried doing anti-virus and trojan checks, spyware checks, disconnecting from the web (that was another problem, where my web connection kept dropping out and only a re-boot would rectify it). none of which solved the problem. My advice is, bite the bullet and do a secure wipe of your hard drive (from a bootable CD like Hirens or DigiWizs' miniPE²-XT v2k5.09.03, multi-purpose bootCD) then re-instal windows without any of the updates that were released after September.
