@MCT For what he has, 350 is enough. If he starts adding a lot of stuff to his machine then he might need to upgrade, but what he has will work fine. @Philliman You're probably looking at either CPU, RAM or HDD. You could try swapping out your IDE cables, too (and make sure the ones for your HDD are 80-wire. e.g. ATA66/100/133). If swapping the cable doesn't do the trick, there's some tests you can run to test your components. Memtest86+ Ontrack DataAdvisor One thing to keep in mind is, if Memtest comes up with errors it could be either CPU or RAM. A bad CPU can cause errors in Memtest just as easy as bad RAM, though it won't necessarily do that.