Alright, I ran driver sweeper, and reinstalled the GTS 250 device, but I'm now getting this message:
"Windows cannot start this hardware device because its configuration information (in the registry) is incomplete or damaged. (Code 19)"
EDIT: Nevermind, I restarted my computer and the drivers reinstalled correctly. This still hasn't solved the blue screen, though, I started up a game to test it out and after 15 minutes or so it blue screened.
Thanks for all of the help so far