BSOD: Page Fault, fried mobo??

I've been working over in the Windows 7 support forum, but have been directed here as my problems have evolved. Here's my thread:

http://www.techsupportforum.com/f217/windows-7-setup-failure-495568.html#post2795464

And here's the deal thus far: I have had problems with my system for a while now. It worked fine when I purchased it in 2006, but a few months ago I started seeing some malware and, perhaps separately, a nv4_disp error. Here are my components:

Motherboard: Asus P5n32SLI-SE Deluxe

Graphics: nVidia 7950GX2

CPU: E6600 Core 2 Duo

PSU: Silverstone 750W

HDD: Seagate Barracuda 7200.9

After a move, I wanted to see if I could get it functioning again. Previously, Windows (XP) hung at the user login screen (when it got past nv4_disp). This time, it hung at loading personal settings. Then, I got a new error, Page Fault in a NonPaged Area. I tried removing RAM and booting, same problem.

I then decided to wipe and install Windows 7 cleanly, thinking the HDD was the issue. Installation went smoothly, until during a routine reboot, Windows failed to start-up correctly. Startup Repair alternately cannot repair the problem, or can't find one. I've run memtest on RAM and SeaTools for my HDD. No problems.

Then I turned my PC off and on, heard a zap, and smelled some smoke. I'm seeing lights on my motherboard and PSU, but my pc won't turn on. I have no idea where to go now. Any help will be greatly appreciated. Thanks.