How to make my Compaq Persorry'o act like a computer

Ok Im fed up with this piece of scrap metal, Its a compaq Persario 6000 which the idiot where i bought it from said it was a gaming computer, which he was as wrong as humanly possible, it has NO AGP slot and a ONBOARD video card that cant even play runescape (For you who play runescape its a joke).

anyways its as slow as hell. i added a freaking Radeon 9200 SE PCI card into it, WHAT DO YOU KNOW it has 0 power so it constantly shuts-down out of nowhere, it ALWAYS has a problem every day, i dont think there is a single gaming computer out there that doesnt get an error at least once a week.

Besides the shutting down, 10 minutes to fully load up, sometimes loads up something out of nowhere, not ending programs i told to end three hours ago, turning on netscape for no apparent reason, cant go on internet explorer part of my comp its ok, PLEASE TELL ME WAYS TO ADVANCE THIS RUST BUCKET.