My OS is Vista Home Premium and my Autorun stopped working

I purchased my computer a year ago and I am running Vista Home Premium. A couple weeks ago I noticed that my Autorun is not working. I checked the registry and every thing there is correct. I can see the CD/DVD drive in "Computer", I can play a movie or CD if I go into applications like Windows Media or Media Center, but when I check Disk Management the CD/DVD drive is not listed, it use to be there.

I am not sure how: 1. to get my Autorun to work again
2. get the CD/DVD drive to show up in Disk Management

If anyone has any suggestions I would greatly appreciate them. thank you in advance

 

For the first problem: Open Control Panel, Select Hardware and Sound, Under AutoPlay, select Change default settings for media or devices.

 

I tried that first but nothing happened. It is so strange because I can plug in my external HD and it goes into autorun but not the CD/DVD. I know they are different but I would think if it could do it for one why not the other.

Thank you for your help, I appreciate it