pretty pink and green squares then crash

My system is crashing after about 45 min running. The screen will get vertical lines sometimes green and pink squares (can still see everything just through green and yellow) then the whole screen and soon after a message saying an error has occurred. saves file to hard drive and shuts down. Will restart but still has problem. Have to let cool down or seems so before good restart. Have cleaned inside well and still having problem. Have attached SF tool file.
Thanks Joe

It seems you may have heat crahes.

Open the side panel, btw thks for filling out your specs, and make sure the video card fan is turning.

Also get hwmonitor from www.cpuid.org It'll tell your your temps of the cpu and gpu.

Post up the temps, and we can go on from that angle too.