Windows 7 White Screen

[evosinite]

everytime i start up my computer it works fine for about 5 minutes and in that time, im actual able to play some games and stuff but then my screen freezes and then turns white. is there something wrong with me GPU??

my system specs are:
intel quad core q6600 2.4ghz
Crucial 4gb ddr2 800 ram
diamond ATI 4670 1gb ddr3

ive never had this problem before and ive only recentiy started encountering it today after trying to overclock my gpu by 5mhz. is it possible i did something wrong??

 

[Jimbo22]

Is that 5.0 MHz or .5 MHz on the OC? I would recommend going back to original settings on the GPU, then start the OC in increments of tenths, one at time, (example; 3.0 original, increase to 3.1) then check how the GPU works while gaming. If that increase works well then do it again and see how it goes until it becomes unstable again. Also when overclocking make sure you bump up your fan speeds to counter act the heat build up on the GPU as well as your case fans to help all-around case cooling.