Is this from a Recovery Disc or partition or a Window's install disc with a key. Main thing's: back up any data you want to keep because it'll be gone, download and burn your AV installer (favorite's too and whatever else) to install after the reformat because I disconnect from the net, computer driver's on a CD (if an install disc because I lose the internet anyway), your key (if an install disc), setting computer to boot from CD and, optional, but some type of Recovery system like Drive Image, Macrium Reflect, Acronis True Image, Ghost, Paragon (some free, most not to back up your system to a new state after a reformat, more program's too), might even make an image before, in case. At least, you'll be back where you began. A little reading: http://www.techspot.com/vb/topic53502.html (don't need to delete anything because it's going to be gone after)
One thing to keep your eye on after choosing to install Window's; make sure it's to the same partition Window's is currently on or you'll wind up with a new Window's as well as the old one. You'll see the option, just pay attention. I didn't the first time and wound up with two install's.
