PC hardware: Is my processor or motherboard fried?

Is my processor or motherboard fried?

Recently, my computer has been running especially slow. In the Windows Task Manager, I noticed that the CPU is running at 100%, a stretch from its normal rates of 10 to 20%. At first, I thought it was a virus, so I ran various scans, but nothing came up. I went into the BIOS, and it stated that my CPU was 1.5 Ghz, instead of 2.4 Ghz. Also, I noticed that the temperature of my CPU was about 80 degrees Celsius. I shut down my PC, and opened up the case. I reattached the HSF, and noticed that one of the clips for attachment (tricky LGA 775) had been bent. Presumably, the last time I messed with my HSF (about 18 months ago), I had installed it improrperly. After reinstalling it correctly, I booted up. I checked my BIOS, only to have my computer shut down on its own. This happened a few times, whether I was in BIOS or just trying to boot up as normal.

Basically, my question is whether or not any of my components are fried. Thanks in advance.

My system (custom build):

Windows Vista Premium 32-bit with SP1
MSI P6N Platinum Motherboard
Intel Core 2 Duo E6600 @ 2.4 GHz (never OCed)
2 GB DDR2 800 Corsair RAM
250 WD Caviar 7200 RPM
Antec TruePower Trio 550W
LG 18x DVD/CD Burner
ATI Radeon X850GT 256MB
Case: Antec P180