Windows® 8.1 Keys; Keyboard As Numeric Keypad - Asus PU451J E-Manual

Windows® 8.1 keys
There are two special Windows® keys on your Notebook PC's keyboard
used as below:
Press this key to go back to the Start screen. If you are
already in the Start screen, press this key to go back to
the last app you opened.
Press this key to simulate the right-click functions.

Keyboard as numeric keypad

Press
as number keys or as their original keyboard function.
40
Turns the speaker volume down
Turns the speaker volume up
This Notebook PC comes with 15
select keys that you can also use for
numeric input.
to toggle between using these keys
Notebook PC E-Manual