The Administrator is not tied to one ITP/Server setup. It can administer, in theory at least, an infinite number of ITP/Server set-ups. To add an existing set-up the Add ITP/Server installation menu item can be used.
After selecting this menu item a browse window will pop-up. In this window the ITPWORK folder of the setup that you want to add, can be located. You can add any set-up as long as the account running the Administrator has Read/Write rights on its ITPWORK folder. However, these rights are not enough to Stop/Start the ITP/Document Processors of the added setup. The Security chapter's ITP/Server Account, explains which rights are needed to do that.
An ITP/Server set-up can be removed by selecting it and selecting the menu item Remove ITP/Server installation. Note that the setup is only removed from the Administrator; its files are still present in the file system.