It's no fun when the box is empty
Step-by-step guide to fix Turn Windows features on or off: dialog box is blank or empty in Windows 7
If you recently upgraded to Windows 7 or performed a clean install of Windows 7, the first thing you should do is run Windows Update to get the latest security patches and fixes.
However, it is also possible that you get an error message with the error code below:
Or if you go to Control Panel and click Turn Windows features on or off, you might see that the Windows Features dialog box is empty.