How to: Stop an Instance of SQL Server (net Commands)

To stop the default instance of SQL Server

  1. From a command prompt, enter one of the following commands:

    net stop “SQL Server (MSSQLSERVER)”

    -or-

    net stop MSSQLSERVER

 To stop a named instance of SQL Server

  1. From a command prompt, enter one of the following commands. Replace instancename with the name of the instance you want to manage.

    net stop “SQL Server ( instancename )”

    -or-

    net stop MSSQL$ instancename

ms190236.note(en-us,SQL.100).gifNote:
Stopping an instance of SQL Server with the net stop command causes SQL Server to perform a checkpoint in all databases, saving all changed data to disk.

http://technet.microsoft.com/en-us/library/ms190236.aspx