Major computer problem

[Thythe]

This isn't for my computer, so I might not have all the specifics. Basically a friends computer crashes all the time. It will get the blue screen of death and just turn off. Then it won't turn on again for hours, but will eventually work again. This friend already reformatted their hard drive and started from scratch, but the problem persists. I'm guessing it's some major hardware issue that can't be fixed but just looking for opinions. Thanks.