Confirm that the issue is with Windows Task Scheduler by creating a simple test task that attempts to run an exe or batch file such as Notepad.exe. If the same error occurs and Credential Guard is enabled, try disabling Credential Guard and test again.
If Credential Guard cannot be disabled, try modifying the Scheduled Task to run as SYSTEM:
- Open the RMAD Console
- Right click the collection and go to Properties | Agent Settings
- Ensure "Use the following account to access Backup Agent and backup files" is enabled
- Enter the user account if need be
- Launch the Windows Task Scheduler
- Select the task for the selected collection
- Right click and go to Properties
- Click the drop down next to 'Configure for' and select 'Windows Vists, Windows Server 2008'
- Change the User account to SYSTEM
- Save the changes
Note: If either of the following Local Security Policies are enabled on the RMAD server, the will first need to be disabled to make the above changes:
- Network access: Do not allow storage of credentials or .NET Passports for network authentication (Windows 2008)
- Network access: Do not allow storage of passwords and credentials for network authentication (Windows 2008 R2, Windows 2012)