How to access second monitor from another machine remotely which has a single monitor?

It's more like a workaround: In the remote connection window on your demo pc, use Alt+Tab to bring the window to the front, then press Alt+Space, choose "Move" on the popup menu, then use the arrow keys of your keyboard to move the window until you see it.

Dual Monitor without remote Desktop:

• Use ( Windows Key + Shift + Left/Right Arrow Keys) in order to move from one window to another window in Dual monitor.

Dual Monitor with Remote Desktop:

If you are using Remote Desktop on dual monitor, do following steps in order to move using keyboard

• First, use (Ctrl + Alt + Pause/Break) it will select and resize your Remote Desktop.

• Use (Windows Key + Shift +Left/Right Arrow Keys) in order to move from one window to another window).

• Use Ctrl + Alt + Pause/Break) it will select and full screen your remote desktop.

You can either move your application like the above answer mentions

(alt+tab) - to select the application

(alt+space) - to open options

(m) - to start moving

this will not work if the application is already fullscreen. In that case,

use (alt+space) and (R) to restore the application

and then use (alt+space) and (m) combination to start moving

Another way (not sure if this will work on < windows 10) is to use

win+shift+ctrl+(left/right) after selecting the application