You need to do 2 things.
1. Register the graphic data to printer's flash memory as logo data.
2. Set Windows driver to print the registerd logo data.

One thing you need to know is that there are 2 different logo command sets
to save/print logo data. (Old command "FS p/FS q" and new command "GS ( L")
The saving logo command and printing logo command must correspond each other.
We recommend to use new one. Following explanation is for new command.
(Default setting of utility/driver in the explanation is for new command.)

1. Registering logo data by POS Printer Utility
It is recommended to use POS Printer Utility.
The utility can be downloaded from
http://www.citizen-systems.co.jp/english/support/download/printer/utility/software/index.html#POSPrinterUtility
Using "Logo Setup" function of this utility, you need to "Add image" and "Regist" it to the printer
with Key "L1" to "L5".  If you use other key, you cannot print the logo from Windows driver.

2. Setting logo printing on Windows driver
Go to the property page of the Windows driver
And move as follows
  General Tab => Preference button => Advanced button
Then you see detail settings of the driver.
On the very botton of the settings, you can find "Logo Printing".
There are 6 positions to print logo and on each position, you can choose Logo1 to Logo5 or None.
If you register logo data as L1, you need to choose Logo1.  L2 => Logo2 .....

If you finish these steps, registred logo is printed automatically when you print receipt
by the Windows driver with logo printing setting.