Run the following commands (copy and paste and put into a batch file)
Basically stops windows update service, registers dll's, deletes any updates sitting waiting to be installed, then starts windows update service and forces through updates
net stop wuauserv
regsvr32 /s wuapi.dll
regsvr32 /s wups.dll
regsvr32 /s wuaueng.dll
regsvr32 /s wucltui.dll
c:
cd %windir%\SoftwareDistribution
rd /s/q DataStore
mkdir DataStore
rd /s/q Download
mkdir Download
DEL %WINDIR%\WINDOWSUPDATE.LOG
net start wuauserv
net stop "Automatic Updates"
net start "Automatic Updates"
wuauclt /resetauthorization /detectnow