If cleaning the lenses of your laptop's drive doesn't help then it means it's laser is either very weak or about to die. Manufactured DVD's are (as said) silver and therefore very reflective, so even a weaker laser reads them. Drives are more or less compatible with recordable DVD media (or viceversa) so sometimes it can be just a matter of finding the right brand of recordable DVD. But if you have problems with all recordable DVD's then the culprit is the reader.