A friend gave me his laptop for a Windows Update problem, and I thought I would share this simple fix. The error stated that WU couldn't check for updates because the service is not running, you may need to restart (wrong, it was running). Here's what fixed it:
Click Start Type: cmd Right click on cmd in start menu and select 'Run as Administrator' Type: net stop wuauserv Hit Enter Type: ren c:\windows\SoftwareDistribution softwaredistribution.old Hit Enter Type: net start wuauserv Hit Enter Type: exit Hit Enter