Here are some things to check:
1. TURN OFF THE PC. Verify the connections are securely plugged into the PC. Be careful to plug the connector in properly, without bending the pins. It only plugs in one way. Try to line up the pins and verify the connection is seated well.
2. Now verify the connections are secure for the adapter cables and the keyboard Y-connection.
3. Verify the cable that goes into the handle of the scanner is pushed in securely.
4. Verify, if possible, that the scanner is plugged into the keyboard port and not the mouse port. Sometime there are small icons to aid in locating the proper port.
5. Turn on the PC / Computer. If it still isn't working, you may need a power supply, or the scanner may be defective / DOA. Please call for assistance.