My computer has crashed two times, shutting down my monitor but with all the fans running. Each time, I have to reset my GPU for my computer to recognize my GTS 250. I have played Starcraft 2 for hours at a time before, with settings on ultra with no problem.
Today in the morning, upon playing 20 minutes of campaign, my computer crashed, loosing connection to my monitor, however with all my fans still running. After restarting my computer, my computer did not recognize having a GTS 250 installed, and thus I had to reset my GPU from my motherboard. Detecting it afterwards, I installed the most recent drivers for it. Thinking it was over, I tried playing Starcraft 2 campaign again, but before I could even start a mission, the same thing happened again.
CPU: AMD Athlon II X3 445
GPU: XFX GS-250X-YDFU
PSU: XFX P1-650X-CAH9
RAM: OCZ Reaper HPC 4GB - DDR2 1066
HDD: Some Sanyo IDE I took off of my External HDD, 250GB
Well your temps seem to be fine.If you have overclocked your card(I think you havn't or gts 250 would hav shown greater temps) bt anyway you should go back to the stock values.
Or check whether your card has fitted properly in the slot and that there is no loose connection
I can't find any other suggestions.
Try checking if same probs occur while playin other games
And regarding drivers you should always go for those in your card's manufacturer's technical support site
I had the same problem with 2 pc's #1 was athlon 2 620, 4 gigs gskill ram, 8800 gt 500watt psu, 64bit vista.
#2 athlon 6000+, 2gigs corsair ram gigabyte 5770, antec 750 watt psu 32bit vista. both systems cpu temps were under 40c 8800gt 80c 5770 55c problem fix with a fan added to each south bridge and it solved the problems hope this helps.