wireless keyboard problem

Windows 2000 OS, MS wireless optical desktop and that’s the problem. The keyboard on 3 of the 6 computers will stop working. Using the wireless transceiver and connect buttom on the keyboard sometimes reestablishes the connection, except in one case where nothing has worked. I’ve changed the batteries in the keyboard, reinstalled drivers and moved devices all over the desk trying to maintain a connection. Technet no help. I’m stumped, any suggestions.

thanks