Fix Windows Update Error: "Files required to use Windows Update are no longer registered or installed"

"Files required to use Windows Update are no longer registered or installed"

Fix that worked for me (XPSP3)

1. Download older Update Agent
http://go.microsoft.com/fwlink/?LinkId=43264

2. Make a shortcut to the .exe file

3. Right Click the shorcut - select properties

4. On the Shortcut tab, add /wuforce after the path in the Target (example:"...\WindowsUpdateAgent20-x86.exe" /wuforce"

5. Run Update - It will act like "Microsoft Update" was never added.