Can anyone offer some computer advice?

[whatcaneyedo]

I'm having a computer issue and I was wondering if anyone could help. What happens is if I have a couple of programs running the computer crashes. Its as if someone just pulled the plug and the whole thing loses power.

The PC is 8 years old, runs Windows XP and is an ASUS. These problems only just started happening in the last few months. Until now, aside from the occasional virus this computer has had very few problems over its lifetime. I've reformatted it 3 times already this year and I've been trying to do it again but the process seems to make the computer work too hard and then... it crashes. I'm now convinced that its a hardware issue and considering the age I think I'm better off just to buy a new machine. Maybe a Macbook... but I dont really want to spend the money right now.