Hard Drive will not format

I was trying to do a clean install of XP Pro and I cannot format my 320gig
hard drive. I had my C & D both on this hard drive with a 30gig partition for the OS. Someone tried to help and they got the D partition deleted but I still get to the point of running the format command. When I boot up with the OS CD in the drive I go automatically to the window to put in my name and company information and then to input the key. I tried downloading a disk from Microsoft to allow me to format the drive but it would not work at all. Any help will be appreciated.