DVD drive is not running or reading my discs.

Hello,

My name is amber. I own a HP Pavilion g7 with windows 7. My computer always read dvd and software disc as soon as i put it in the dvd drive. It would run automatically. For reasons unknown, it quit running or reading anything. I don't know what to do. I am a photographer who needs my drive to work so i can burn disc for my business. I also need to re-install my printer from a disc and its not working. I also used my computer regularly in order to watch DVD's. What can I do to fix this problem?