Chances are that your friend's computer has a hardware problem, not something in software that you can scan for. Capacitors on the main board that go bad are a common source of many problems, including freezing and no startup.
It's a fairly simple matter to replace the bad parts and get the computer going again, although some experience with electronic repair, soldering, and the proper tools are required to prevent damage to the board during the repair.
Several sites offer information about how to open the computer, showing where to find the usual culprits, and giving pictures of what the caps look like when they are bad. There are several with videos as well. Kits that give you all the capacitors needed are available from several sources.
Here's the place I used, but you can find others.
Good luck with the repair, and thanks for using Fixya!