Under construction

I bought a Radeon Powercolor HD3850 about 6 months ago, to add a year or two to my aging AGP system. It seems like it's been one long blue screen of death since I installed it.
My computer has always had its quirks, and even though I've been able to play Runescape almost turned all the way up since installing the card, I can no longer deal with the constant bsoding, crashing and failure to boots that have come with the new hardware. I could do nothing but ٩๏̯͡๏)۶ when I tried playing KOTOR for nostalgia's sake and my machine straight up bsoded. I acquired a copy of KOTOR2 and the same happened. Once again, I could do nothing but ٩๏̯͡๏)۶.
Mind you, I've tried every solution, patch and hotfix I've found on the tubes, but to no avail.
I will try to fix my system one last time before giving up hope of ever finding a solution. I will document my last attempt here.
First, I'll uninstall my current 8.5 drivers. I'll (hopefully) reboot, run drivercleaner (thank you afterdawn) and reboot again. Then I'll install SP3, shut the system off and see if I can feed the card more power. Start up again and change the AGP aperture to 256 from the BIOS (I read somewhere that Powercolor recommended this.) Boot Windows, install the 9.6 hotfix drivers. Anything that can be fixed should be fixed at this point. I'll (try) update this entry before I go to work.
-Update-
Fail. Working on safe mode.
Did all that and increased the AGP voltage to 1.6 and it still BSODed when I booted. I'm gonna try to start it up again in an hour and/or after work. If it boots like before then at least I'll have SP3 and new drivers. If not then I'll just read Atlas Shrugged instead of playing KOTOR. At least Rand understands my troubles...
-Update update-
Hurrah! I didn't try to start it until this morning and it worked, to my surprise. Catalyst Control Center is pretty cool. And I don't know if it's the new drivers or Catalyst or SP3 but my display is way sharper. Now I can play DotA with AA. Mama mia!

TL;DR version:
New graphics card=bsod. New driver, bios setting and control center later still does, but performs better.