E-Mu Xboard 25 Owner's Manual page 15

Introduction
4. Select Don't Search, I will choose the driver to install, and click Next.
5. Select E-MU USB-MIDI Device, and click Next.
6. After a few moments, you will see the Microsoft Digital Signature warning.
Click Continue Anyway.
7. You should now be using the correct driver. It may be necessary to reboot
your computer at this point.
Xboard 15