Program crashes and blue screens

[Acidkat]

My processor fan went out a little while ago, and I bought a new one. But for some reason a day or two after I put the new fan on any program I run will just crash at a random interval. There is no rhyme or reason for it, except that it does not seem to like internet browsers and any sort of game. Sometimes It also blue screens with no reason ( any time a program dies, it gives me no additional information as to why it failed.) Since this all started I have reformatted my HD and bought new RAM in the hopes that somehow someway those might be the problem. I have ran and am running a video stress test as I am writing this, to see if maybe the cards started to turn on me.

I am currently running:
Intel 2 Dual core 3.1 GHZ
2 Nvidia Geforce 8600 GTS
4 Gigs DDR2 800 MHZ RAM
800 Watt PS
and of course a 350Gig 7200 RPM HD
and two additional fans I put on to make sure it stayed nice and cool.

Any help would be appreciated thanks in advance

[BipolarBill]

There is probably a problem with the thermal connection between the heatsink and CPU. You must use a proper thermal conductor (usually a grease like Arctic Silver) between them. It must be applied properly too. It should be spread thinly and evenly. If not, the CPU may overheat and cause crashes or even shutdown.