From the Start Menu > Control Panel > Programs and Features > Click 'Turn Windows features on or off', open up Media Features and untick Windows Media Player. Click "Yes" then "OK" and then restart the device.
Once Win has restarted > Control Panel. Open Programs and Features, Click 'Turn Windows features on or off', open up Media Features and untick Windows Media Player. Click "Yes" then "OK" and then restart the notebook > restart your PC or notebook again.
Next, carry out the following process to force Windows Media Player to re-build the Library Database.
A useful utility for viewing all the files on your PC is called Free Commander, on the link below, as it displays folders that the Operating System normally hides and has a good search function.
This is a zipped file. If you don't have an extraction utility installed, download and install 7-Zip which can be used to open this so that you can run the installer.
Make sure Windows Media Player and Windows Media Centre are closed.
Launch Free Commander, double-click Users, double click 'your username', double click Local Settings, double click Application Data, double click Microsoft and double-click Media Player. Delete all the files that have the extension .wmdb - do not delete any folders.
Close Free Commander and open Windows Media Player - it will now begin to rebuild the library database which may take a while.