First, check the Microsoft KB http://support.microsoft.com/kb/931712

If these suggestions don't work, some customers have also reported success by following;

"In the Administrator: Command Prompt window, type the following commands. Press the Enter key after each command:

DISM.exe /Online /Cleanup-image /Scanhealth
DISM.exe /Online /Cleanup-image /Restorehealth"
- From http://answers.microsoft.com/en-us/windows/forum/windows_8-windows_updat...