My PC wasn’t getting it’s updates from our on site Windows update server.  Follow these steps to get the updates directly from Microsoft.  This worked for me on Windows 8, should be good for Windows 7 too.

1. Open registry editor (Start menu –> Run –> regedit)

2. Find the following path HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU

3. Change the value of the UseWUServer from 1 to 0 (double click on it, change the value and click OK)

4. Restart Windows Update service (Start menu –> Run –> services.msc –> find the Windows Update service and click on Restart)

You may find group policy sets it back next time they are applied

Orignal source