Yeah, you'd need a proper Windows installation CD to install after a full format......unless shops have now started to give out "ghost" CDs that restore your system to factory-default with Windows and default programs installed. I've never ever bought a pre-built computer from a shop, so wouldn't know...
I have the unfortunate please of support on Branded PC support. The manufacturers put a 2 gig partition on the drive with the Pre-Build Image on it. Yeah great until the hard drive dies. Grrr.
Bring back the CD Ghost images.