connecting second hand wireless keyboard

Recently i have bought an Apple wireless keyboard from some one, and the keyboard has been used.

I would like to know if i can set the wireless keyboard up on a:

-Windows 7 laptop,

-iPhone 4s.

If it is possible to set the keyboard with these devices, i would also like to know:

-How to set the keyboard up,

-If i would need anything else, other than batteries, to set the keyboard up.