You can manually install the client by modifying the following in Notepad :
REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate]
"WUServer"="http://server:8530/"
"WUStatusServer"="http://server:8530/"
"TargetGroupEnabled"=dword:00000001
"TargetGroup"="default"
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU]
"NoAutoUpdate"=dword:00000000
"AUOptions"=dword:00000004
"ScheduledInstallDay"=dword:00000000
"ScheduledInstallTime"=dword:00000003
"UseWUServer"=dword:00000001
"RescheduleWaitTimeEnabled"=dword:00000001
"RescheduleWaitTime"=dword:00000002
Save as wupdate.reg and import into the registry. Then run wuauclt.exe /detectnow to detect the WSUS updates.