- Power off the DAC
- Unplug the USB cable from both ends.
- Restart the PC
- Uninstall the PS Audio USB driver from the "Program and Features" control panel
- Restart the PC
- Install the latest PS Audio USB drivers from the Downloads section (but don't connect the USB cable until you are told to.)
- When the install process asks for you to plug in the USB cable, power up the DAC and plug the cable in on both ends.
The install should finish correctly.