Go to My PreSonus to register your device using the serial number found on the bottom of the unit.

The installation process differs significantly depending on your operating system: AudioBox® USB - PreSonus

PreSonus regularly updates their software; look for the most recent version of Universal Control (e.g., v4.x) compatible with your operating system. Installation Guide for Windows vs. Mac

Technical Analysis and Operational Guide: The PreSonus AudioBox USB Driver Architecture