The first thong I would suggest is make sure the server is fully upto date.
Run Windows Update and click thelink that says get updates for other products find out more. Follow the instructions to install Microsoft Update. This will run Windows Uodate but for all Mcrosoft Products installed on your server.
If it wants to install a WSUS/Windows Software Update Servicelet this happen but once it has installed the service and starts the configuration wizard just close the wizard. Otherwise SBS won't be able to manage WSUS