Shutdown, Restart

Here is my problem. I recently went to a friends house and showed me that there computer will not shutdown nor will it resart using the Shutdown button. I starts shuting down the computer but then it just goes back to normal. I tried using File Checker and Scan Disk to look for missing or altered files and it found nothing. Scan Disk does not work I think because they have not defraged there computer sense they bought it 1 year ago. That’s another issue.