When you select the server and click Restart in the IIS Manager console, the Terminal Services Gateway service will be stopped and not restarted, even though the World Wide Web Publishing service is restarted. If you are logged into the server via RWW or a TS Gateway session, your connection will be dropped and you will not be able to get back in via RWW or TS Gateway. In addition, the following event will be logged in the Microsoft-Windows-TerminalServices-Gateway/Operational log. Keep this in my mind when working in IIS Manager on the SBS server remotely. Use iisreset /noforce instead or restart the World Wide Web Publishing service in the Services console.

Source:→ SBS Blog