Even if there are no backup jobs currently defined for a specific drive, the option to create a new recovery point set may be grayed out with the following error message.
The recovery point set option is disabled because you have already assigned a selected drive to an existing recovery point set backup job. You can only have one recovery point set defined for each drive.
1. If the backup jobs have already been deleted and the recovery point set option sill remains to be grayed out while creating a new backup job: