Do you have a question about the HP K4000 and is the answer not in the manual?
Identifies the Slim Bluetooth Keyboard, pairing button, power button, and battery compartment.
Insert 2 AAA alkaline batteries into the keyboard's rear compartment.
Slide the power switch on the keyboard to its power-on position.
Enable Bluetooth discovery mode on Windows 7 by right-clicking the icon and selecting 'Open Settings'.
Enable Bluetooth discovery mode on Windows 8 via PC settings to allow device detection.
Press the pairing button, add the device in Windows, and enter the PIN code.