Booting/rebooting is the startup process of the computer. You do it every time you turn the computer on or restart it.
You want to whipe the drive and reinstall the operating system, that's NOT rebooting!
Apparently, your computer don't have a factory reset partition.
Get an install CD (windows XP) or DVD (Windows vista, 7 and 8). You can download a copy that you can burn on a CD or DVD.
Boot from it and do a normal install.
(downloading a copy of Windows to replace/repair a broken installation or reinstall is legal, you are in a gray area)
You also can install Linux. It's very easy. Just get a copy of any distribution that you can download and burn on a CD. Boot the computer with it. Chose install. Chose what language you want.
(as Linux IS free, there are NO legal risk or uncertainities)
Electro, January 2013
