need more info on your setup, but windows 7 is the fastest windows install I have ever seen, 30 minutes for a clean install. 20 hours is obviously a problem... maybe a bad DVD or drive. are you upgrading or doing a clean.install. just need more info
i am doing an upgrade from windows vista. everything was going fine all the items in the install box loaded and are checked then it went to program and files transfer and has stalled there. the install is 70 to 80% complete.