Comp Freezes And Can't Do Shit!

[Ahh...]

So here is the story about my lovely 2003 HP.
When I turn it on and do something like 5-15mins it just FREEZES! And I don't what's the problem.
Yes I had Troijan there but I deleted and it should be gone. Still keeps going.

So help me if you can.

[iNFoRMaLiTY]

Do another Full virus scan and a Malware/Adaware scan. If they both show nothing I would have to think it could be a cooling problem. Take the side off your case and/or the whole case and see if its getting hot... or put a fan on it see if it runs longer.