DVD/CD WRITER DOES NOT RECOGNIZE MEDIA

Hello,
My DVD writer shows up in my computer as "E" but does not recognize that there is a cd or dvd when you put one in. When you click on the drive it says "please insert a disk into driver". I have an HP Lightscribe DVD writer/CD writer and I run windows XP. I used it a lot to burn cd's and dvd's but now it won't even read commercial cd's or dvd's. I had tried uninstalling Roxio to install a newer version (which I never could get to run right), could I have deleted something?

I have run the troubleshooter, cleaned the drive, uninstalled and reinstalled the driver, etc, all the standard fixes but nothing is working. Could I have deleted something from the registry or programs that is keeping it from seeing the media but not making it show up errors?

Help.

Thanks in advance,