Windows simply won't run efficently.. if at all.

ASRock N68-S UCC motherboard
AMD Athlon 7750 dual core 2.7ghz processor
4 gig patriot ddr2 ram
Nvidia 9400 GT

Okay. I originally got BSOD'd while trying to install vista with the driver_irql_not_less_or_equal nvstor.sys. i was able to bypass this by messing with the bios disabling various thing while limiting voltage on the RAM, shutting off sound card, etc.. Now that I finally (after 4 days) have managed to install windows, it now barely runs. First time after install it worked (slowly, but managable), when I noticed my internet wouldnt go above ~2kb per second so i shut it off, went to look up a solution, then when I tried to boot up again, I couldnt get into windows whatsoever and was forced to reinstall. So I did that again, and now it's even worse. It takes 10-15 minutes to simply log in, then just to get the "welcome center" window up and the computer to stabilize, another 10 minutes (then if i try to do anything, forget about it). This is if it even can get to the log in screen to begin with (i've sat for up to 20 minutes and nothing)

There is something seriously wrong here and I do not understand how. I do not want to sit here and reinstall again seeing as though that didn't help. I reformatted the hd before freshly installing windows. Everything is in place in the computer. Does anybody here, that knows more about computers then I do, know whats wrong?

Seems like there is an issue between Vista and some component of your computer. Have you tried any other OS? The nvstor.sys looks to be an nvidia driver crash.