Class Not Registered?????

Hi about two days ago I began having problems with the sound on my computer.I tried to play music in WMP9 and some error came up I didnt really know what to do so I attempted to play music on my other music program and it worked and when I tried playing music in WMP9 again it started working again so I thought nothing of it .The following day when I turned on my computer I had absolutley no sound I checked just about everything and when I tried playing music in WMP9 another error came up saying'' class not registered''.I soon figured out that I needed re install my DirectX and I did but everytime I try to play music in WMP9 I still get the same error although the sound on my computer is working fine.and I tried uninstalling WMP and it didnt work and reinstalling the setup and it doesnt work.Can ANYBODY HELP ME IM SERIOUSLY DESPERATE thankx