Ensure that you have the correct entries for your Windows Update Server, settings and schedules in the registry. They should be located in:
Open a command prompt on the client and type wuauclt /detectnow and click enter
Then open the Services menu and restart the Automatic Updates service
This should then re-initiate connection with your Windows Update Server and operate as per the settings in the registry in terms of how the updates are delivered to the client.
If there is still an issue it is worth checking the Windows Update logging which is located in C:\Windows\WindowsUpdate.log