Thank you for contacting us. We'd like to help you resolve this issue. The first thing I noticed about your device manager screen is that the Serial port is not recognized. When the serial port is recognized, under Ports (COM &LPT) you should see something like "Galileo (COM# )" as shown here:
Before trying to update the firmware, follow this guide to make sure your host machine has the serial drivers that will allow the Galileo Firmware Updater tool to communicate with the board. There are instructions to install the drivers here: http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-galileo-boards/000020786.html http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-galileo-boards/000020786.html
Let us know if you manage to install the drivers and update the firmware. We'll be waiting for your response.