Re: what to do
I would put linux on it...
Can't reccomend a distro without specs.
Though, a shot in the dark, I'd try Puppy Linux if you don't know much or **** Small Linux if you know something about linux. Both of those are extraordinary on older hardware.
Antec 300 Illusion
430w Antec Earthwatts
AMD Q4 640 Propus
2x4gb Patriot DDR3 1333
750gb Seagate 7200.11 Hard Drive