The Kensington PS2 Mouse Driver is a software package that allows your computer to communicate with a Kensington mouse that connects via the PS/2 port. PS/2 (Personal System/2) is an older type of connection used for keyboards and mice before the advent of USB. While PS/2 ports have largely been replaced by USB, some older systems and mice still use PS/2 for communication.

The Kensington PS2 Mouse Driver is required to enable advanced functionality like adjusting mouse settings, controlling the mouse pointer speed, and customizing button functions. Most basic mouse functions should work out of the box with Windows, but for enhanced features, you would need to install the appropriate driver.