Check The Temperature Of Your CPU
if your PC keeps crashing for no apparent reason, and if those crashes  tend to occur when the machine is busy doing lots of things, there’s a  pretty good chance that the problem is down to an overheating CPU.   Maybe one of the fans in your system has stopped working, or an air  vent is blocked with dust. 
To help diagnose such problems, here’s a wonderful little Windows  utility that tells you the current internal temperature of your CPU.  If  the chip has multiple cores, it’ll even give you a separate reading for  each. And if there are multiple CPUs, that’s catered for too.
It runs on Windows XP and above, and supports a wide variety of CPU  types from Intel and AMD.  And it’s only a 0.5 MB download.  Plus, it’s  available in 32- and 64-bit versions, including a portable version that  can be run  directly without needing to be installed. 
The program is called CoreTemp, and you can get it from    www.alcpu.com/CoreTemp. 
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