How to: Start SQL Server Agent (net Commands)
The SQL Server Agent service can be started by using Microsoft Windows net commands.
From a command prompt, enter one of the following commands. Replace <instancename> with the name of the instance you want to manage.
net start "SQL Server Agent( instancename )"
net start SQLAgent$ < instancename >
For information about running SQL Server Agent in verbose mode for troubleshooting, see sqlagent90 Application.