This is a known issue with some update for WMP but it has a simple fix.
Reboot your system.
Open cmd.exe as an administrator by
Click Start. Type Command. Right-click Command Prompt, and then click Properties.
On the Shortcut tab, click Advanced.
Select the Run as administrator check box.
In the command box type in
unregmp2.exe /UpdateWMPVersion
Press enter.
Or you can use MS Fix it for me tool found here http://go.microsoft.com/?linkid=9758651
After the download just run the file that is downloaded