Unstable PC

[Jun aka Pekto]

Is my PC nearing its death? It's an old P3 system.

I haven't found a virus (even when scanning in safe mode) but it still keeps on restarting while running Windows 2k. My virus definition files are up to date. It also stops while its running on Ubuntu Linux.

Could this be hardware problems already?

Thanks!

Everyone seems to have made good suggestions. I was going to suggest taking the thing apart and re-assembling it again and then see if the problem shows itself.