A little more information about the computer, laptop/desktop, operating system, brand name and model number, age of the machine, etc. would sure help.. And if this is the same computer that you've posted about recently, please try not to make new posts about similar subjects.
In the meantime, if reinstalling Windows doesn't fix the issue and especially if it's the same laptop mentioned before, then I'll guess that hardware is the issue.. Either the power supply or motherboard need to be replaced. Heat is a common culprit with laptop computers.
Hope this helps.
My pc keeps freezing randomly. To get the system to work again i keep having to do a control,alt delete and then press x twice.
I have reinstalled windows but that has not worked. My virus software picks nothing up.