All you do is run the Windows XP cd, and that should guide you through the process of reinstalling the OS, and after that load each of the driver cds. Should take a while though.
Oh shit, that beats my brother's records, and that's saying something. I'd recommend an OS Reinstallation or an OS Upgrade personally, because having 1000 threats on just 4000 files is pretty feckin' bad. Only thing I can really say now is glhf.