I recently got a computer from a friend and he had a problem with it shutting down so i figured it was a virus.. I delted 2 partitions he ha on there and tried to reformat but i cannot get through the reformat stage because the computer constantly shuts off.. What can I do? I dunno what is causing this Please help me

I would look for hardware problems first. First the psu. If you have another to use, run that for awhile. If shutdown persists reseat the cpu with thermal grease and be sure that the fan is down tight and cooling as it should. If there are multiple ram modules, try one at a time just in case one has become bad. Better yet, try a different known working ram module. Cables working and secure. You could ask your friend for all the recent history that you can get on the machine. (changes just prior to the shutdown situation).

Well He has had this problem since he built the computer last year.. and its gotten so bad where i cannot even reformat now.. there was a 256 and 512 ram stick i took 256 out but havent tried putting a new one in from this comp.. I reall dont know alot about computers so IN detail PSU? Ect would help alot..

To check if the cpu is getting proper cooling you could enter the bios by pressing anywhere from delete to any of the function keys when the first screen show up, the main page should show specs like cpu speed and temperature, if its something like 80 degrees celcius then the fan isn't doing its job if its like 30c then thats not the problem. After check for loose wires preferably unplug everything and replug everything just to be sure, heck if you could rebuild the whole thing it would be even better, it isn't that complicated. Look for any signs of physical damage to any of the components that smallest sratch could mean replacement other than that its hard to help, good luck.