Windows 7: Gateway NV53 Processor Speed

Just yesterday I noticed that my Windows experience index scored my processor at a 2.9 when it has always been way higher than that. It caused me to investigate and download a program called CPUID to see how my processor was actually running, and no matter how hard I tried I couldn't get it to go higher than 800MHz. As of recent my laptop has been getting extremely hot and sometimes overheating and shutting down (even though I can hear the fan running)... Is it possible that my computer is running so hot that it's attempting to protect itself from overheating by locking my computer to run no higher than 800Mhz?

I have a Gateway NV53 with an AMD Athlon II Duel-Core M300 2.00 GHz processor that is running Windows 7 Home Premium 64bit.

How old is the laptop ? is it possible although the fan is running, the vents are partially blocked with dust etc - is the heat outlet on the side or the bottom ? do you use it on a desk or your lap ?

It does sound like it is under clocking due to heat.

Put the processor under a load and then try to run cpu-z or whatever ou have handy. Most laptops will throttle down the processor when nothing intensive is going on.