Shall we ask Coggy what CD she has first?
Is it a full OEM CD with drivers etc or an upgrade CD?From what you have said before I'm guessing it's a full OEM CD with drivers and additional software.
If its an OEM CD then more often than not it's just a case of booting from the CD.
Put the CD into the drive, go into your start menu and choose "turn off computer" and from the next screen "restart".
Your PC should shut down and then go through it's restart procedure, at some point during this there is normally a message about pressing a key to boot from the CD.
Follow the instructions on screen and choose to FORMAT the hard drive.
The instructions here are good
http://www.winsupersite.com/showcase...p_sg_clean.asp
If you read through any of the posted instruction links and have any problems understanding them just post back and I'm sure we will all chip in to get you through it