http://www.linguistsoftware.com/winch.htm

http://www.worldlanguage.com/Products/Chinese-Windows-XP-Pro-OEM-Simplified-With-Optical-Mouse-Spanish-Operating-Systems-Professional-Edition-OEM-105154.htm

http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=%22chinese+windows+xp

These links too may prove enlightening:
http://www.microsoft.com/windows/ie/ie6/downloads/recommended/ime/default.mspx

http://seba.studentenweb.org/thesis/howto-winxp.php

This link will get you to the Chinese Microsoft site where you can locate legitimate local retaqilers:
http://www.microsoft.com/worldwide/default.aspx