So let me get this right... You get distorted Audio only when you try to play music from your CD/DVD Drive, is that right?? And when you play MP3, which is on your HDD it works fine, correct??? If this is the case, how many CD Drives do you have?? If you have 2 CD Drives, then try downloading the following File and run it and let us know what happens, infact even if you have 1 CD Drive, download it and check it:
When you run this file, you will see nothing happening on the screen... Double Click on the File, wait for 10 - 20 Seconds and then restart the computer and then try to play some CD and see if it helps you or not... Let us know what happens.