Alienware M17x r4 doesn't boot: believe gpu or driver issues?

My Alienware has not been able to boot properly for about two weeks now.  It began when the screen suddenly went black and everything presumably ended (all sound stopped, etc...), but the computer was still powered on for about 5 minutes without anything happening.  I turned it off and on again, and it began performing a windows update.  Just as the windows update was finishing, it froze.  It stayed frozen for about 30 minutes, at which point I had no choice but to turn it on and off again.  At this point, it would boot up to the windows icon and then freeze (I let it sit for over 30 minutes and nothing happened).  I could, however, boot in to safe mode with networking.  

I tried many things here to no avail, including: system restore, startup repair, repairing the windows installation from the disk, boot with last known good configuration, BIOS update, hardware diagnostic (no problems were found), etc...  Eventually, after looking through the boot logs, I found three drivers that were not loading during regular boot attempts (the ones that lead to freezing): vga.sys, dxgkrnl.sys and NDProxy.sys (there are always 4 instances of this one not loading in the log).  When I tried disabling the GPU (I have a Radeon 7970 with an onboard intel 4000) and using only the onboard graphics, I was surprised to find that the computer could boot without issue.  The problem, naturally, is that I now cannot use my GPU.  If I re-enable it, the computer freezes at the windows icon again like before.  I tried many different sets of GPU drivers, but none of them fixed the problem.  In addition, the device manager tells me that, with respect to the Intel 4000 card, "Windows has stopped this device because it has reported problems (Code 43)."  This is confusing because this is the only video card currently enabled and I can still see things.  The hibernate option is also blocked.  Command prompt tells me that "an internal system component has disabled hibernation" (I can post the full screenshot if needed).  Interestingly enough, when I tried to change the Intel 4000 drivers, the computer became unbootable again.  I was forced to boot in safe mode and roll back the drivers in order to make it work.  Finally, when I disabled switchable graphics with the f7 key and used only the 7970, the computer also become unbootable.  Additionally, there were random lines and color distortions all across the screen.

At this point, I am considering either reinstalling windows completely (which I would prefer to avoid since it will wipe all the data) or buying a new gpu (which is worse, since they are pretty expensive).  I plan on reinstalling the OS as the next step, unless anyone else has any ideas.

Sorry if anything I mentioned is irrelevant, I just tried to tell everything I know at this point.  I will be glad to provide any additional information/clarifications.  Thanks for any adivce!