Hi,i have a problem which desperatly needs sorting,i built a pc around 8 months ago and up until about a month ago things were running sweet,then all of a sudden whilst playing BF Vietnam my fps went down dramaticly from avg of 150 fps to abou 40 fps,then out of game it does a number of bad things 1)BSOD telling me recent hardware is not installed properly,2)Screen just freezes and multi coulored lines appear,3)PC justs shuts down or reboots.Now i have tried just about everything,new motherboard,2 differant graphics cards,a new hard drive,changed the memory,installed all the latest drivers for everthing,tried all the older drivers for everything and all to no success,hopefully someone can point me in the right dirrection has this has gone way over my head and leaving me a bit out of pocket,here are my specs.....
AMD 64bit 3000+ (skt 754)
Gigabyte K8ns Pro
1 gb pc2700 333 DDR memory
MSI Nvidia Ge-Force FX 9000 256DDR
650 Watt Power Supply
Windows XP Home (SP1)
Thanks for taking time to read this and any kind of help would be a gods end.

Can you post what the BSOD error message was exactly?? Also, how hot is it inside when the system goes wongly.