How to Control Your Windows 8 Tablet's Touchscreen
Press and hold.
The equivalent of a mouse right-click, touch the item and hold down your finger. A second or two later, a square will appear onscreen. Lift your finger, and the square becomes a menu, just as though you’d right-clicked the item with your mouse.
Example: Press and hold your finger on a blank portion of the Windows desktop. When the square appears, lift your finger; a menu appears, enabling you to choose between your desktop’s options.