Computer Automatically shutdown

Reasons:
1.    Processor Overheating
2.    Computer Virus
3.    Faulty Power Supply


Solutions:
•    Processor Overheating

Check the heat-sink of the processor  if it’s clean. If not try clean it with a soft brush like paint brush.  If the Heat sink is dusty then the processor will over heat that causes automatically shutdown.


•    Computer Virus

Scan your computer with malware remover and anti virus visit the link  below to give you instruction. Virus can cause automatically shutdown.
http://pcuserguidetech.blogspot.com/2010/12/how-to-remove-computer-virus-or-malware.html


•    Faulty Power Supply

Try a known good power supply