How to solve the problem of computer repeatedly acts frozen and reboots automatically?

Apply the following remedial measures in case my computer repeatedly acts frozen and reboots automatically:

• If the cooling fan set over the CPU does not move or cool the system properly, this problem occurs. In that case

• Switch off the power, and after opening the cooling fan,

• Check it out. If the fan is faulty, replace it.

•check the fan behind the CPU while the computer is running;

• The problem persists if the computer has any virus. 

• Clean up every drive of the hard disc by running an upgraded anti-virus. Besides, it happens due to the installation of new hardware or program. In that case, 

• Uninstall the program and run the computer.