What's wrong with my internal dvd drive 16x?

Let me explain my problem. First of all, i have a 16x dvd rom drive that's internal. When i put my dvd in the drive, nothing pops up. Not even windows media player or any player. But i have another dvd drive, a dvd ram drive that reads dvd roms.

The external dvd ram drive is only 8x, so therefore i can't install dvd rom games on the external drive, because my dvd game requires 16x dvd drive. Now when i have my external dvd ram drive install, and i put a dvd in that drive, a flash player pops up and i can listen to my dvd.

So, what could be wrong with my internal dvd drive that is 16x? It won't install any dvd rom games, please help. Oh yeah, if its neccessary to say, i use windows xp professional.