so i tell you shortly my problems:
when i use my computer about 30minutes,whole system freezes.then i must "reset" system from power source-simply cut off the power.next thing is: i go looking at my bios settigs:
Advanced/IDE configuration/ primary ide master:NOT DETECTED Ans i m 100% sure: there is hard drive and it it s connected to my motherboard,with ide cable and cable connection is very good .
then i have cut power off,again for few minutes.start computer again and i can use my computer about 30min and then same "roadshow" starts again.
and here is my system:
power source 450W,motherboard Asrock K7NF2-raid-latest bios version(1.3 if i remember it right),Seagate Barracuda 320gb hdd(IDE),1532mb ram,geforce 6200 256mb graphcard,soundcard(onboard:c-media) OS:windows xp home sp2. Pioneer dvd burner (s-ata)
and here is dxdiag file too... so can you help me???

Sorry no one responded juha - are you still having problems?

Understand that you are describing classis over-heat problems. You need to make sure your system is clean of heat trapping dust and dirt and that all fans are spinnng freely. Do not overclock.

sounds like a heat issue, but it wouldnt hurt to run memtest86 to check for a faulty ram stick, which can cause strange problems.