The drill seems to be to install the driver first and then connect the piano to the computer. That said, the standard USB midi driver which windows should load is probably OK.
here's the relevant bit from the manual. As you see from the bit in bold, if you get it installed correctly you should see the piano as a Midi device:
4. USB port
When the CA piano is connected to a computer via a commercially available USB cable, the CA piano will be recognized as a MIDI
device. As with a regular MIDI interface, the CA piano will be able to transmit and receive MIDI messages.
There are A USB port and B USB port. Connect a computer to the A port and digital piano to the B port.
About a USB driver
For data exchange between a computer and digital piano via USB connection, software (USB-MIDI driver) must be installed on the
computer for proper digital piano operations.
Please read the following instructions carefully as a different USB-MIDI driver may be necessary depending on the computer OS.
Windows XP / Me users:
The standard USB-MIDI driver installed on Windows will be used. This USB-MIDI driver will be automatically installed when
the unit is connected to the computer.
To establish MIDI communications with the unit by using an application, select "USB audio device" to defi ne the unit as a MIDI device.
Windows 2000 / 98SE users:
You need to install the specifi ed, special USB-MIDI driver. Download the special USB driver from the KAWAI site as shown below,
and install it on the computer. http://www.kawai.co.jp/download_demo/driver/
Read the instruction manual thoroughly before connecting the unit to the computer, and make sure to install the driver.
If you connect the unit to the computer without installing the driver, the USB-MIDI driver may not operate properly. If
this occurs, use the driver update function of the OS to install the appropriate USB-MIDI driver, or delete the driver by
using the driver delete function and then install the driver again.
To establish MIDI communications with the unit by using an application, select "KAWAI USB MIDI IN" and "KAWAI
USB MIDI OUT" to define the unit as a MIDI device.
Macintosh OS X users:
When the unit is used with Macintosh OS X, the unit will be recognized as a MIDI device automatically; therefore, no special
driver is needed.
To establish MIDI communications with the unit by using an application, select "USB-MIDI" to defi ne the unit as a MIDI device.
Users of Macintosh OS9 or earlier:
The unit does not support Macintosh OS9 or earlier. Please establish a MIDI connection by using a commercially available
Notes on USB
When MIDI and USB are connected simultaneously, USB will be prioritized.
When connecting a digital piano to a computer by using a USB cable, fi rst connect the cable and then turn on the power of the
When a digital piano is connected to a computer by using a USB cable, it may take some time before communications start.
When a digital piano and a computer are connected via a hub, and the operation is not stable, connect the digital piano directly
to the USB port of the computer.
Operations of a computer or a digital piano may become unstable if the power of the piano is turned on or off, or if the USB
cable is pulled out or inserted during:
* Driver installation
* Computer power-up
* MIDI application operations
* Communication with the computer
* Standby in power-saving mode
USB may not operate properly depending on the settings of your computer. Read the computer instruction manual thoroughly
before use and ensure that appropriate settings are made.