Error: "Failed to install agent, failed to copy file ... used by another process" when attempting (4236111)

Failed to install agent, failed to copy file C:\Program Files\Quest Software\Recovery Manager for AD\ERDAgent.exe as it is being used by another process when attempting to perform a backup.

This occurs when a previous backup terminated unexpectedly and failed to stop the ERDAgent.exe process

RESOLUTION:

1. Open Task Manager on the DC that is failing to backup and select the 'Processes Tab'
2. Find the ERDAgent.exe process, right-click on it and then select End Process
3. Delete the %windir%\system32\erdisk folder to confirm that the process has been terminated successfully
4. Retry the backup

This applies to all versions of Recovery Manager for AD.