I found the following two-line answer, I hope can help you . 1、Inside the Control Panel, open Regional Options, in the Language settings for the system selected SimplifiedChinese (If you want to have the election on Traditional Traditional Chinese), and then select Set Default in the Chinese PRC, and then in the Your Locale (Location) elected Chinese PRC, and then Click OK, based on when prompted, enter the installation path on the I386 directory, and then restart according to prompt it. Such as adding the Chinese character input method, you can input Chinese. And the normal use of the Chinese version of the software installed. 2、The English version of the system by default does not support Chinese display. If you need to display Chinese, the East Asian language pack was installed. Is as follows: Click "Start" → "Control Panel" → "Regional and language Options" → "Languages", check on "Install files for East Asian Languages" option, click the "OK button, the system languages installed package after the restart, you can display Chinese. If you are prompted during the installation process to insert the installation disc, you'll need to install the English version of Windows XP CD-ROM CD-ROM Add to complete the installation.

Usually you don't need to configure the browser, but it's important that you also install the support for East Asian languages on your operation system. In case of WindowsXP: Windows XP and Server 2003 include support for East Asian languages. To install the files, check the Install files for East Asian languages in the Control Panel > Regional and Language Options > Languages. Note that a minimum of 230 MB of disk space is required. If it doesn't work: Which browser are you using?

I agree with Mimi's. Accept for Mimi's method, maybe you cann't input Chinese character, then 1. to find Setting in input bar, click it, 2. In Popup window (maybe named Characer service and inputting, I don't know it definite name because my pc is Chinese system), click Setting-->adding, find PRC or Taiwan zone, It's OK 3. If you find that you input phonetic, maybe you should set keyboard's setting

I'll leave this suggestion again too. If you want an easier way to input characters, after you install the language pack, you can install the Google Pinyin input system. It's very convenient, and a lot of people I know (Chinese and non-Chinese) use it. http://www.google.com/ime/pinyin/

install the support for East Asian languages on your operation system