Suggest you download the latest version of the Windows Update Agent:
http://download.windowsupdate.com/v7...gent30-x86.exe
Save it, do NOT run it, close the browser and any other open programs
Now run "WindowsUpdateAgent30-x86.exe"
If you get a message that the Update Agent is already installed, then go
to Start > Run > click the Browse button
Navigate to where WindowsUpdateAgent30-x86.exe is located and click on it
Click the Open button
At the Open: line, click once on "WindowsUpdateAgent30-x86.exe"
It should be highlighted in blue
Click just *after* the last quotation mark - "
Push the Space Bar on the keyboard and type in
/wuforce
The command should now look like this
"C:\<wherethefileislocated>\WindowsUpdateAgent 30-x86.exe" /wuforce
[Notice the space after the last quotation mark]
Click OK or press Enter
Restart the system