The ThinkPad UltraNav Windows driver is a software package developed by Lenovo to support the UltraNav input system on ThinkPad laptops. UltraNav combines two input devices: a TrackPoint (a small, red pointing device in the middle of the keyboard) and a TouchPad (a flat, touch-sensitive surface that functions like a mouse). The driver is necessary for Windows to properly recognize and configure these devices, providing full functionality, customization options, and enhanced features like gestures and sensitivity adjustments.