Did you make sure that your power cable was secure into the wall and the PC? Is your surge protector (or UPS) still protecting? Is it securely plugged in?

The computer restarting after the power loss is not strange, that is a common BIOS setting, to either Power On after a failure, or to go to Previous State (on if on, off if off).

By reseting other connections, you could have taken care of part of the problem.

Can you monitor your computer's CPU temperature? I have seen CPU's go bad, as well as cooling towers (yes those) a few times. There are many things to consider.

Could it be a virus, yes. But it's easier to rule out hardware first (IMHO). and Freeze ups are likely to be software. But there are so many ways software can go bad, it's quicker to rule out hardware.

__________________
I'm here, you may now make your next two wishes.

Beat Me, Whip Me, Make Me Use Windows!!

Every Piece of Electronic Equipment runs on a finite amount of smoke. The systems are normally very efficient at reclaiming the smoke and recycling it, however, should you do something to let the smoke out, your system will become useless.

SAVE THE SMOKE !!

New PC :
New: Phenom 9500 Quad 2.2, 4gb ram XP Pro 64-bit (Sata 0), XP Pro 32 bit (sata 1), 40 eide HDD (music), Pioneer Blu-Ray Burner, HP Multidisk CD-RW/DVD-Rom, 2x250 Seagate HDD's, ATI Radeon 3870, Asus M3A32-MVP Deluxe WiFi-AP

Old PC:
P4 1.5GHz, 768 Ram, hda-80Gb (80Ubuntu), DVD R/RW