To verify preferred credentials for the Enterprise Manager Agent:
Login to Enterprise Manager as the system administration user.
Go to Preferences, Preferred Credentials.
Find the Agent target and click Set Credentials.
In Target Credentials, enter the HostUsername and Password of the Enterprise Manager box so the agent knows how to login.
Tips
If you are running Enterprise Manager on Microsoft Windows, the Target Credentials must be for a Windows user that has log on as a batch job policy enabled.