How to: Stop an Instance of Notification Services (SQL Server Management Studio)
Each instance of Notification Services has an engine on each server that runs a hosted event provider, generator, or distributor. Typically, the NS$instanceName Microsoft Windows service runs the Notification Services engine. You can stop all Windows services associated with an instance of Notification Services by using Microsoft SQL Server Management Studio.
This procedure does not apply to clusters. On a cluster, you must use Cluster Administrator to stop the Generic Service that is configured to run the instance's Windows service.
To stop an instance of Notification Services
In Object Explorer, expand the Notification Services node.
Right-click the instance of Notification Services that you want to stop and then select Stop.
Notification Services attempts to connect to each server that runs the NS$instanceName Windows service and then stop the service. A dialog box displays the status for each service.