GT 650M Error 43

I own a Lenovo Y400, with Nvidia GT 650M graphics, and I have been having some problems.

A few weeks ago, I started seriously tinkering with my laptop, installing a ramdisk, upgrading the wireless card, flashing a custom BIOS, et cetera. Somewhere during all of the tinkering, I screwed up, and made the laptop barely usable -- Frequant crashes, and couldn't sleep/hibernate -- so I restored a disk image that I had made earlier, and put in my old network card. The only difference was the custom BIOS, in which I set everything to default. All of the problems went away, except for one: Every few minutes, I would get a few seconds of blackscreen and a message about a crashed kernel driver, and my GPU would die. I went in the device manager, and learned that the GPU was throwing an Error 43, saying that it is "reporting problems". I would disable and reenable the GPU and all would be right. For a few minutes. Recently, however, the disable-reenable hasn't been working. I uninstalled the drivers, reinstalled them in safe mode, still no dice. The laptop mostly works, but a few things -- Basically any game, for example -- don't. On occasion, the GPU will work for a while, but it usually ends up dying, or BSOD'ing my laptop. I plan to try installing the oldest driver I can find, but I really don't have high hopes.

Has anyone else had this problem? Any ideas on how to fix it? Should I just give up and send it in?

 

Have you tried doing a clean Windows install?