Ok Gaz, i think you're gonna end up listening to too many peoples advice here, LOL.

You need to do it one way, ideally from one person who knows the complete way of doing it.

But for starters, you're going to need a way of formatting your Hard Drive, easiest way is using a Windows Start Up Disc. Im just trying to find you a link so you can download the necessary files (assuming you can put them onto a floppy in your computers current state) and then i can advise further on what to do and what to type and when etc.