I am not a professional but, I am trying to install a Sony Rewriteable drive to an XP computer for a friend. Her existing dvd/cd drive is the master and I installed her Sony as the Slave. The new drive is recognized and it can read the cd's. But, when I try to play a CD in the new drive, the sound is muffled and slow and then it corrects itself. When I tried to burn a CD, the CD did burn but, the sound came out the same on the CD, muffled and slow. I then went to my computer at home to see how I connected mine. I noticed when I installed my Rewriteable, I have a CD Audio Adder connected from my regular CD drive and Rewriteable to the mother board. Do I always need a CD Audio Adder???? I really do not remember if it came with anyhing or if I bought it.