If youre having problems getting a CD to work in your computer because its scratched, there are some easy solutions. First, try cleaning the CD with a little dish detergent. Use your finger to gently rub the detergent on the CD and coat it real good. Dont use a cloth, it can make more scratches and defeat your purpose. Rinse it off well with water and try the CD in the drive again. If you are still getting read errors due to the scratches, then its time for the unlikely solution: toothpaste. Yep, you read it right. Put a little toothpaste on a Q-tip and polish the scratched area until they disappear or until they cant get any smoother. Then wash the CD in water. That should hopefully fix it. If not, just retry polishing with toothpaste. If a few cleanings do not solve the problem, then try a metal polish such as Brasso in the same manner as the toothpaste. There is also a solution that involves gently rubbing Vaseline on the CD from the center outward. But Im of the opinion if it goes that far and the CD still cant be read, then its time to trash it.
Something else to consider: If your CD drive has trouble reading CDs or DVDs that arent scratched, then you need to clean...