Hi Ivrunner C 兄, english version of MS Win XP did not installed the chinese input method by default. Apart from the installation, would you know any chinese input method like 倉頡, 速成 or 九方 ? 先了解而後安裝, 繼而再做輸入練習. 倉頡 or 速成 is part of chinese input method from MS Win XP. You can follow the steps what ckleung told you to install.九方 is a thrid party input method but it is quite easy to pick up. Here are link to help you to understand the said chinese input method.
hi ivrunner c hing , pretty much what CK hing and Gills hing have talked about,
theres still a web chinese inputting system in yahoo hk dictionary if you cant install any of those softwares (or you dont want to, haha)
hope it helps