Install your Rack ES software disc. The Rack ES is a USB-compatible device, but the software is necessary to establish communication between the device and the computer. Insert the installation disc in your PC, click the installer and follow the installation instructions on your screen.
Connect your ES Rack to your computer. The Motif ES Rack includes a USB A (rectangular) to USB B (square) cable. Connect the square end to the "USB" jack on the back of your ES Rack, and the rectangular end to an available USB port on your computer. Turn on your ES Rack by flipping the "Standby/On" switch on the back of the device.
Connect a MIDI keyboard to your device. The Motif ES Rack is a sound module, meaning that it can produce and manipulate high-quality sounds, but it requires the assistance of a MIDI controller such as a keyboard to play the notes. Connect one end of a MIDI cable to the ES Rack via the "MIDI In" jack, and the other end to your MIDI controller/keyboard via the "MIDI Out" jack.
Open Cubase LE. Click "Devices" on your menu bar, select "Device Setup" and choose the "VST Audiobay" from the left column of the pop-up menu. Here you can view and change your audio input and output options.
Click "Master ASIO Driver" and select the "Motif ES Rack" option from the drop-down list. Click "OK" to confirm. Cubase will now recognize the rack for audio input, and you can transfer sounds from your keyboard through the ES Rack and into your PC for recording.