I put in the OS X disc this morning to upgrade while I went to school. It restarted and went to the grey screen with the in the middle of it. I decided to let it chill out and load while I went to school. When I got home, the grey screen was still up. I have hard reset-ed it around 5 times now, but each time it just takes me to the grey screen. Is there any way I can at least take the disc out of the computer?