I received a question about removing servers in Azure Backup the other day and thought I should point out where to remove them in Azure Backup. In the Azure Classic Portal -> Recovery Services and the Backup Vault where the servers are, click Registered Items and Delete the servers. By default, the Type is “Azure Virtual Machines” so don’t forget to change to the type you want to delete. See the picture below for details.
If you get the following error message “You cannot delete vault XXXXXX because it contains registered servers. Delete the servers and the restore points for the server data, and then delete the vault” during Azure Backup Server installation and setup delete the server as described above.