My CPU boots normally and the PC keeps working for sometime but suddenly it shuts down. My antivirus application is regularly updated and PC is routinely scanned.
There is no set pattern as sometimes it shuts down after 10 minute of usage and then on rebooting works for hours. But it does shutdown all by itself now and then.
I have checked and cleaned the RAM in case it has any particulate matters which might be causing problem.
Download Orthos and Realtemp or Coretemp. Run orthos, start the test, run Realtemp, see what temperature your CPU gets to under load. It could be an overheating problem. Which can be fixed by cleaning and re-attaching the heatsink with some fresh thermal paste. This is not a difficult task.
there are instances when the power supply might be the problem, try using another one, and check also if all the power connectors are connected including the 12+v connector, I have seen machines with the same problems and it worked.
As I had mentioned in my post, last couple of days my PC used to boot and I was working normally and it suddenly just shuts down by itself. No error nothing. I was not aware of how to check the CPU temp or the Fan speed. By the time I got the advice, my machine just booted and then within a minute or so shut down by itself. Now it has gone to the hardware guy, he has changed the SMPS and kept it under observation for a day. Is there anything else that I should have noted?