What is the key on the floor good for

Hint 1 of 6:

It operates a hidden switch.

Hint 2 of 6:

The key is located just to the right of the desk.

Hint 3 of 6:

LOOK SHIELD on the statue - why would anyone touch the shield ?

Hint 4 of 6:

MOVE SHIELD.    +5

Hint 5 of 6:

USE KEY ON KEY BOX in statue.     +5

Hint 6 of 6:

MOVE SWITCH just below computer screen to turn it on.   +1