Adding a runtime server requires a server machine to be added to the Favorites folder of the Administration Tool.
There are several ways to add a server machine:
Using the Domain and Network Neighborhood nodes, navigate to the required server machine.
Then either:
Right-click the machine name, select All Tasks > Add to Favorites.
Drag and drop the machine to the Favorites folder.
Alternatively, right-click the Favorites node and select Add Server.
Enter the name of the required server machine and click OK.