Please start a command prompt (Start > type "cmd", right click it and choose Run As Administrator) with elevated access rights and use the following command. If the GUI is not starting for some reason, it's likely that the file contains errors.
Type the following command and make sure you have Windows installation CD at hand:
sfc /scannow. The command will scan for integrity of your system files. If there's something broken, this command will fix it giving back functionality of the application.