I get that error message if I'm not on the Home Page, but you are on the Home Page so that isn't it.

Is the installation complete? With KN2600, USB and Win XP notebook once the driver was installed I had a second set of steps to follow. In the Control Panel/Sound and Audio Devices, I had to choose,configure,install the Panasonic USB MIDI. If you like I can post the steps but perhaps you have done this? If so we'll just have to put our thinking caps on