The payment window does not operate normally because the payment module has not been installed properly. In general, a pop-up window asking for installation of activeX appears automatically. However, if it does not appear due to the computer settings, you can check the detailed explanation from the URL provided in the customer center at the top of the shopping mall.
http://www.kcp.co.kr/popup/20080118_vista_xp/vista_xp_popup.html