SQLServerAgent could not be started (reason: Unable to connect to server '(local)'; SQLServerAgent cannot start).

 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.MSSQLSERVER\SQLServerAgent

 C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\Log\SQLAGENT.OUT

 2013-01-28 20:02:34 - ! [298] SQLServer Error: 780, SQL Server Network Interfaces: The logon attempt failed [SQLSTATE HY000]
2013-01-28 20:02:34 - ! [298] SQLServer Error: 780, Cannot generate SSPI context [SQLSTATE HY000]
2013-01-28 20:02:34 - ! [000] Unable to connect to server ; SQLServerAgent cannot start
2013-01-28 20:02:34 - ! [298] SQLServer Error: 780, SQL Server Network Interfaces: The logon attempt failed [SQLSTATE HY000]
2013-01-28 20:02:34 - ! [298] SQLServer Error: 780, Cannot generate SSPI context [SQLSTATE HY000]
2013-01-28 20:02:34 - ! [382] Logon to server failed (DisableAgentXPs)
2013-01-28 20:02:34 - ? [098] SQLServerAgent terminated (normally)

 SQL Configuration manager -> SQL Server Agent -> Logon User -> NT/Local Service