Attempting to start or restart the Backup Agent service results in an error stating "Error 1069: The service did not start due to a logon failure." This may have occurred after a system or domain user changed their logon password.
This error is caused when the Backup Agent service attempts to use its stored logon credentials to authenticate. If the stored credentials do not match the current credentials, the logon failure will be generated.
Click on the "Start" button in the taskbar or hit the "Windows" key to bring up the start menu.
Type services.msc and hit the "Enter" key to open the Services window.
Right-click on the Backup Agent service and select Properties from the menu.
Go to the Log On tab to change the service's logon credentials. You can switch the service to use a different user profile or you can update the password for the user profile it is currently using.
Click Apply at the bottom and OK to save any changes you have made.