Alienware m17x wont read dvd rom. Plays cd's but not games or dvd's
 

I had to set my alienware m17x to its orginal factory setting.I read installed all three disc's. I then installed divx when I noticed it wouldn't play youtube videos,My picture view was also not working as well. NOW,it plays Cd's but when I put a dvd in or a game disc the light comes on for a few...