Try resetting the keyboard's memory of wireless apple keyboard, Power it down, then power it back on but keep the power button pressed for 3 seconds. Make sure Windows 7 is using the correct driver. Go to Device Manager -> System Devices and select Bluetooth HID Device. Go to the Driver tab and click "Update Driver" Select Browse my Computer, then "Let me Pick". If it shows you more than one available driver with exactly the same name, you have to eventually choose the Microsoft one to get the keyboard to work properly.
In the Windows 7 task bar, click the Bluetooth icon and select Add Device.
Next right click on your device's icon and select Properties. If your device isn't listed, try turning it off and on or just mash the keypad or click a few times.
From the Properties dialog, in the Services tab, you should see a checkbox item for "Drivers for keyboard, mice, etc (HID)" under Bluetooth Services. Make sure that is checked. Open up 'Devices and Printers'
Click 'Add a device'
The computer will scan for your keyboard, which may come up as just 'keyboard' or as an 'Apple Keyboard'
Select use your own Passkeys and type in 1111 using your existing keyboard.
It will now be waiting for you to enter the same password on your Apple wireless keyboard. Key it in, press return and your keyboard should be paired with your pc.
