To allow remote desktop (RDP) to use multiple screens do the following.
Start remote desktop
Click show options on the bottom left

Select the display tab
Check the use all my monitors checkbox

Return to the general tab
Click save

To allow remote desktop (RDP) to use multiple screens do the following.
Start remote desktop
Click show options on the bottom left

Select the display tab
Check the use all my monitors checkbox

Return to the general tab
Click save
