How to Remove a Host
When you remove a host from Virtual Machine Manager (VMM), the host and all associated virtual machines are removed from the VMM database and from the views in the Administrator Console. However, both the host and its virtual machines remain in Virtual Server and you can add the computer again as a host in VMM and manage its virtual machines.
After you remove a host, it is no longer managed by VMM. If a single computer is serving as both a host and a library server, and you remove the host from the computer, the VMM agent remains on the computer until the library server role is removed.
To remove a host
In Hosts view, navigate to the host group that contains the host, and then select the host in the results pane.
In the Actions pane, click Remove host.
If the host is in a trusted Active Directory Domain Services domain, the Remove Hosts dialog box opens and prompts for credentials. The credentials must be for an account that has administrator privileges on the host.