Please follow the link http://www.citizen-systems.com/en/printer/support/software/POS?field_software_printers_target_id=79&field_operation_system_tid=All

Proceed with a selection of Printer Model and Operating system

Continue with driver installation on the page below

Run the installation file and prompt to the end

Please select Printer port

Once installation is complete proceed to Devices and Printers to print a test page

The new device will be displayed in Device Manager as in below

Now, when the test page is printed you would need to select printer in POS Configuration Screen.

Go to File > Configuration > POS Equipment and select Citizen Printer from drop-down menu

Hit OK or Apply