If you undock and then dock a Windows 2000 laptop, your IntelliMouse Explorer mouse settings may be lost, and only the default left and right mouse buttons work?
When you undock, Windows 2000 unloads the IntelliMouse Explorer mouse driver and installs the internal pointing device driver.
When you dock the laptop, the computer BIOS may not unload the internal pointing device drivers and device. Since the PS/2-stype port is NOT Plug and Play, and only handles a single mouse, the internal device takes precedence.
To fix the problem, contact your manufacturer for an updated BIOS.
NOTE: The only workaround is to restart the computer.