You can unregister a Process Engine (PE) server from a farmed PE system. Unregistering a server removes it from the list of servers displayed by Process Task Manager. You might want to unregister a server if you have retired a server or replaced it with another server.
TIP To register a server that has been unregistered, restart the Process Service on the unregistered server.
To unregister a server
TIP If the unregistered server still appears on this or another server in the farm, click Refresh on the toolbar.