Acer Aspire X1935 - Manual (Page 17)

7
English Setting up displays
• Right-click on the desktop and choose Screen resolution.
• Choose the monitor that you want to set as the primary monitor
and check Make this my main display, then press Apply and OK
to change the setting.
• If you want to extend your desktop to the second monitor, select
the secondary monitor, then set it to Extend or Clone, and apply
your change.