The sqlagent application starts SQL Server Agent from the command prompt. Usually, SQL Server Agent should be run from SQL Server Service Manager or by using SQL-DMO methods in an application. Only run sqlagent from the command prompt when you are diagnosing SQL Server Agent, or when you are directed to by your primary support provider.
sqlagent -c [-v]
Indicates that SQL Server Agent is running from the command prompt and is independent of the Windows NT Service Control Manager. When -c is used, SQL Server Agent cannot be controlled from either the Services application in Control Panel or SQL Server Service Manager.
Indicates that SQL Server Agent runs in verbose mode and writes diagnostic information to the command-prompt window. The diagnostic information is the same as the information written to the SQL Server Agent error log.