I'm putting this here since it's only happening when I'm playing games but I'm not sure if I'm in the right place for this.
When I'm playing graphic-heavy games my screen goes black after 6 min (I've timed it) and gives me the message "signal lost" (or maybe it's "no signal"?) and I have to reboot. Anyway, this has been going on for nearly a year. I haven't added anything except regular updates (windows update, drivers etc) and before this started I could play graphic-heavy games without any problems. I even took it back to the store and had it checked for any problems. I described what was wrong but when I got it back they said they found nothing except dust. I took it home to play and the same thing happened again. Nothing wrong, sure.
I've tried to keep it dust-free and cool, used a different screen, going back to previous drivers in case the new one was unstable or something, updated the drivers (and the games when possible) again, changed the in-game options to low or off but nothing seems to work. If I'm very lucky I can play the games for 30-120min instead of only 6min but I've no idea why and I can't get it to happen again with any regularity.
Ordinary games works without any problems. Examples are Broken Sword, Sherlock Holmes, Still Life, Darkness Within and various MMORPGs like Luvinia. Examples of graphic-heavy games no longer working: Two Worlds 1&2, Mass Effect and the Reckoning: Kingdom of Amalur.
I'm using a gaming-computer that's soon 3 years old. I'm not really sure what info you need to know or where I can find it. I've checked the temp with CPUID Hardware Monitor and the Core is 55C-63C and the fan's 65C-72C (if I'm reading it correctly). Is that high or read wrong?
Windows Vista Home Premium, SP2, 32bit
Intel Core2Quad E8200
4GB RAM
NVidia Geforce 9800 GT
Realtek High Definition Audio
Avira Antivir Personal, Ad-Aware, SpywareBlaster