Random Freeze Win7 gtx460

hi guys,

very randomly i started getting freezups. in the middle of browsing my mouse freezes and keyboard nor mouse function, only way out is restart. this is my current setup:

asus p6t deluxe v2 mobo
i7-920 cpu
12gb corsair ddr3 1600 ram
nvidia gtx460 card
1tb WD harddrive

i tried reinstalling the latest nvidia drivers and still happens randomly. any help would be much appreciated.

thanks!