The uninstall agent option is not available for untrusted machines in DPM 2010. Therefore you need to remove the agents manually (Using uninstall program in control panel).
To remove the machine from the agent tab you need to use the remove-productionserver.ps1 Powershell script.
DPM 2010 now supports protection of Workgroup machines and machines in untrusted domains. The agents needs to be installed manually after that you specify the DPM server with the setdpmserver command
Namespace
In configurations where the name space of the DPM server is different then the name space of the protected server. It could be necessary to use the –productionServerDnsSuffix. This allows you to attach the DPM agents in the console using Full qualified DNS name instant of NETBIOS name. The –productionServerDnsSuffix should specify the FQDN of the protected server.
| C:\Program Files\Microsoft Data Protection Manager\DPM\bin>SetDpmServer.exe –dpm servername server01.domain.ad -isnondomainserver -username user01 -productionServerDnsSuffix dmz.local |
