Help Installing Windows 7

So I had Windows XP installed on my mac, but acquired a Windows 7 DVD and I wanted to upgrade! So I deleted my bootcamp partition and then created a new one. When I try to install Windows 7 my iMac restarts and I end up getting stuck on a blackscreen with a cursor beeping in the top left corner. So I restarted my mac and tried to re-install XP, but the same thing happened. The installer for both OS doesn't even load, I get stuck on the black screen. Has anyone else had this problem?