If the official Bontempi driver fails to install on modern 64-bit systems, many users have found success with third-party generic drivers:
For detailed manual instructions, you can refer to the Bontempi PM 747 Quick Manual on ManualsLib. Bontempi 747 Keyboard - Cubase - Steinberg Forums Bontempi Keyboard Pm 747 Driver Download UPD
: Sometimes used as a fallback for generic MIDI devices. Troubleshooting Connectivity Issues If the official Bontempi driver fails to install