Pairing apple keyboard with windows 10
Pairing your apple keyboard with windows 10 is easy, but quite a number of times you would have experienced frustration. Here is what I found that works.
Go to settings > Device > Add Bluetooth or other device > Select the name of your device.
In this case your Apple Keyboard >
At this time press the button on the opposite end of the battery ( or Command + W) compartment and the Green light flickers.
A number appears on the screen enter it immediately on the apple keyboard and pairing should be complete. If you do not do this right away a couple of times, you will get a new prompt where you will prompted to enter a PIN. Do not worry, you will now enter a number which is the new PIN
Now immediately on the Apple keyboard enter the same number quickly and hit enter. Your keyboard will pair instantly. This works all the time.