CPU Overheating, Unique Situation.

Hello, and thanks for reading. Any help will be greatly appreciated.

Anyhow I brushed the dust of my previous desktop. It has a older 775 Intel Board, a old school Pentium 3.2
Dual core with stock heat sink. I never have had any previous issues with it.

While transfering the files I get a thermal shutdown. So i go check the BIOS and it reads 110 Degrees C!
I removed the headsink to make sure that there was adequet thermal paste, and to make sure it was seated properly. All looked okay to me. So i gave it another shot. It did not turn off for the time I had it on, but i figured I go check the temperature. It was @ about 96 degrees C, still hot. So i tried anotherstock heatsink. I also put fresh artic silver paste on the cpu. Anyhow It is still overheating, and I do not feel save running it.

Any suggestions? I was thinking maybe the Mobo temperature sensor/probe is inaccurate. I downloaded CUPID Hardware monitor and it read 35 degree's, but i do not know what to trust. Anyhelp will be greatly apprecited.

Basic Hardware in the Machine. PSU is a POS one I found 350 Watt Max. Video card is extra one from a SLI rig. HD is 1.5 TB Seagate SATA 3.0.
Mobo http://www.newegg.com/Product/Product.aspx?Item=N82E168...
CPU http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Ram http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Video Card http://www.newegg.com/Product/Product.aspx?Item=N82E168...