Maxie808 0 Newbie Poster

The imac acts as if it's about to go to the login window, but never does. The progress bar goes almost all the way across, but doesn't make it. I even tried to do it in safeboot, and it did the same thing. HELP! I think I may have a disc in the dvd drive, so I can't reinstall OS X. I have tried to reboot to eject per info on this site--nothing yet. HELP!!!