How do I obtain a free copy of windows xp? I have a currupt file that needs to be restored and would rather spend my money on windows 7, but can't install that without repairing a boot up file in xp.

You can hook up your hard-drive via a USB connector adapter and grab your files then just format your hard-drive. It will allow you to put Windows 7 on your system without having to use a Windows disk. Unfortunately, I am not familiar with a ISO for free to offer you the files you need. I would ask a friend to use a disk so you can repair the operating system using Recovery Console.