SQL agent not turning on

[DHYEY1]

  I dont know anyhting about SQL. For some reason  i turned sqlagent off and now it is not turning on.the error log showed this,The EXECUTE permission was denied on the object 'sp_sqlagent_update_agent_xps'<c/> database 'msdb'<c/> schema 'dbo'. [SQLSTATE 42000] (DisableAgentXPs). 

To solve i did this,GRANT EXECUTE ON dbo.sp_sqlagent_update_agent_xps TO [Username].

But still it is not working. If someone can help it would be GREATLY appreciated.Thank you for reading.

[#2]

@DHYEY1 

I don't know if this it can you but "The SQL Agent" is a service included in "Services of Windows" and don't start automatically, you have go to Services of Windows and start this service, you can update of "Manual" to "Automatic", I hope to help you.

Regards

[#3]

THANKS!