cd drive doesn't detect dvd

My work computer will not detect dvd's when I put them in the drive. It's a samsung cd-rom sn-124 cd/dvd. After putting the dvd in it will spin then nothing. If I try to open the drive it says "please insert a disk into drive" I thought i needed a dvd decoder. The problem is I need administrative rights to install certain things on these work computers.

Can someone tell me if my problem is that I need a dvd decoder? If so, is there a free one that can be downloaded and not require admin rights to intall? Any advice would be helpful. I did install a VLC media player and that didn't seem to help.

-Thanks.

 

after reading the thread entitled. DVD decoder. I've decided to retract my question.