XFX Radeon 5670

So a year ago, I got a XFX Radeon 5670 around the same time I got a new motherboard. I would constantly get messages saying that 'the AMD Driver stopped responding but has recovered', and quite often I'd just crash to a blue screen. The error reports were less than helpful. I found that when the drivers are NOT installed, it's stable. No problems at all, though some games warn me about my driver being out of date. A few months ago I updated my drivers as a test, and while it still crashed on the first startup (sometimes the second, but rarely) it would then proceed to play beautifully. However, I just moved my computer parts into a new case and the problem has come back with a vengeance. I can't seem to even open a folder without my display locking up and going to blue screen. I tried uninstalling the drivers and deleting any files pertaining to them so that I could go back to just the basic driver that came on the CD, which originally worked fine, but that's not working anymore either. I just want to know if this seems like a software problem (since w/o drivers it seems to work) or a hardware problem, and whether or not simply buying a new card will fix it. Tried other tech forums, but haven't had much luck...

I'm using an Asus M4A785-M motherboard, have an Athlon xII quad core processor, XFX Radeon 5670, and a new 620W Seasonic M12 II Bronze PSU. Please help