I have a self-built PC which is approx. 3 yrs old. I have been gradually upgrading it and I am looking at upgrading the motherboard and processor. However, the system itself is becoming increasingly more unstable. I am running Win98se on a K6-2-450MHz processor. It is a Gigabyte 5AX motherboard with 512MB of SDRAM. The last upgrade was a 64MB Hercules 4500 Kyro2 graphics card (previously 32MB Creative TNT2 Ultra). I have a 250W power supply in the base unit. Could it be problems with the power supply (not enough juice) or Win98 (would XP fix it) or is it because the processor is slow. Is there any software which can 'interogate' my PC and tell me if it is a hardware or software problem? I would like to sort this before upgrading 'cos I only have a limited budget for upgrading.