Windows Media Player

When I attempt to play a CD using WMP I recieve a messge stating that WMP can not read the CD in digital mode and WMP is switching to analog mode. When I click ok on this message it appears that the CD is playing but I do not get any sound. The drive does support digital playback. WMP would play CD’s in digital mode at one point. I started recieving this message after my son delete files but he is not sure what he deleted. Please help.