If for some reason you rely on xkey website for information, its awful the support is non existent, therefore you have to find the files yourself on the wayback machine.

Xkey Piano:


Xkey Plus for Windows


Also if for some reason you’re scrolling infinitely through forums looking for the answer to “Red led is blinking when connected to usb xkey keyboard”, the reason is that the micro usb port is malfunctioning, either due to a bad cable o bad connection or bad unit. Those are the only answers, there’s no reset button and the latest firmware version is 2.4