When a remote desktop window is open, to extend the remote desktop across multiple monitors, select Window > Enter Full Screen from the menu bar or from the expander arrows in the upper-right corner of the remote desktop window. To make the remote desktop fill only one monitor, select Window > Use Single Display in Full Screen from the menu bar.

The monitors do not have to be in the same mode. For example, if you are using a laptop that is connected to an external monitor, the external monitor can be in portrait mode or landscape mode.

You can select a full-screen option from the Settings dialog box after you connect to a server and before you open a remote desktop. Click the Settings button (gear icon) in the upper-right corner of the desktop and application selection window, select the remote desktop, and select a full-screen option from the Full Screen drop-down menu.

You can use the selective multiple-monitor feature to display a remote desktop window on a subset of your monitors. For more information, see Select Specific Monitors to Display a Remote Desktop.