In order to restart the agent through the Remote Services panel, you must have Domain Permissions over the network to access a remote file system. This is just one way that administrators view and manage Windows services on a computer.
Open up Services.MSC from the Admin Tools folder, or the Run command.
From the Services.MSC Panel, you can click on Action> Connect to another Computer..., and either browse for the PC through your AD network or type in the PC name and select Check Names. A GIF is provided below on what this should look like.
From this services window, you will have access to all services available to the machine as if you were sitting right in front of it. At this point, you can find the SVCTCOM service and manipulate it as needed. Make sure to have it running when you're finished.