RCman, did you manage to solve your problem? I have had my pc for a few years now, and it has been doing this crash intermittently ever since i bought it. I managed to live with it, but now, starting to lose work, i cant cope with it anymore!! Since the beginning i have used xp home, xp pro, and win 98, with full disc formats, so i have ruled out any software problems. I have replaced the powersupply unit, and this made no difference. I also have now got a new video card, and sound card. I have two hard discs and have run windows from both. Therefore, i think i am left with the motherboard and cpu to try out. If you have sorted yours, can you help me, or if not, hope this helps you! How can i check the CPU temperature... i have a feeling this may be the culprit? Cheers Ok, I've got my stop error here: 0x0000000A (0x01a90ff4, 0x00000002, 0x00000000, 0x804e65de) It's an 'irql not less or equal error', which they say is most probably a hardware error. How do i narrow this down to the driver /hardware problem?