You can try to solve this issue by following methods:

  1. Use another USB cable.
  2. Use another USB connect port from your computer.
  3. Uninstall the USB driver,then download the latest driver from our website and install it
    http://www.holux.com/JCore/en/products/products_download.jsp?pno=349
  4. Check the COM port number from your computer,and set ezTour to detecting the same COM port

Source: holux.com, translation reworked

Torsten