Internet - CD, DVD, And Other Discs Cleaning
Why? Dirty CDs can cause read errors or cause CDs not to work at all.
Procedure: Use a cleaning kit or damp clean cotton cloth to clean CDs, DVDs, and other discs. When cleaning a disc wipe against the tracks, starting from the middle of the disc and wiping towards the outer side. Never wipe with the tracks; doing so may put more scratches on the disc.
Tip: If the substance on a CD cannot be removed using water, pure alcohol can also be used.