If your Vista/7/2008 machine gets stuck installing/configuring update 3 of 3 after a recent update cycle, you can follow this procedure, but ONLY as a last resort. BEWARE: this may leave your machine in an unstable state. to read about why this occurs, check the following link: The Windows Servicing Guy
- Boot to safe mode, if at all possible.
- Click on Start
- Find the command prompt in the start menu and right click on it
- Choose “Run as administrator”
takeown /f C:Windowswinsxspending.xml
cacls C:Windowswinsxspending.xml /G :F