dont type with weird sudden cap case letters its not good for people who wants to help you coz it makes the text hard to read
but yea go to nVidia.com and then search for forceware drivers and install the latest one.....if the problem still persists then try to reseat your graphics card. if it STILL persists then you might be overheating.
Intel Core 2 Duo E6420 Conroe 2.13ghz
Gigabyte P35-S3 Motherboard
A-DATA 2x1GB DDR2 800mhz memory
Geforce 8600GT 256MB GDDR3 PCI-Express