A basic hardware troubleshooting step when your computer is locking up or spontaneously restarting, especially during the boot-up process, is to reseat the expansion cards in your computer.

Reseating, which is just another way of saying "remove-and-reinsert," assures that the card is making a good, clean connection with the contacts on the motherboard. Expansion cards can wiggle loose and build up dirt over time so the simple act of removing and reinserting them in their slots on the motherboard will often clear up what might have appeared to be a major issue.

Reseating the expansion cards in your PC is pretty easy, even if you've never been inside your computer before. It's certainly worth a shot before buying new hardware or hauling your computer in for service.