DVD wil not read CD's anymore

I dont know when this happened but I an no longer read CD's in my DVD rom. DVD's work fine but it doesnt even register the CD'd in windows, it just asks me to insert a CD. I have tried a few things like removing the device from windows, and letting windows reinstall it, and trying to force it to use othe drivers but nothing works.

The weird part is that the DVD rom will read CD's when it is attached to another computer just not when on its home PC.

I am running Win XP, I have scanned the computer with antivirus, and ehareware removal apps, and I even ran the Sony rootkit removal tool just in case, and I still have this issue. oh and one last thing I have a DVD burner in the same computer that can read CD's.