Unlike many web-based tools Remote Utilities is stand-alone software that always stores its address book on the local disc. This also applies to synchronized address books - in this case the local copy is in sync with a remote address book.
Default address book
Address books are stored as .xml files with each book in its separate .xml file. When you first install the Viewer it automatically creates your first address book called “General address book” that you can populate with folders and records (connections):
The General address book is your default book. Its corresponding .xml file is stored in the current user’s %APPDATA% folder under the name connections_4.xml: