Microsoft Multilingual User Interface

A lot of pre-installed Windows XP on the new computers are English version.
Some of my friends know little English. They prefer Chinese.

So the question is how to convert the task bar and menu list of XP from English to Traditional Chinese or Simplified Chinese.
The answer is Microsoft Multilingual User Interface (MUI).

MUI is an add-on to the English version of Windows XP Professional and Windows 2000 family of operating systems, and will not install on localized versions of Windows XP/2000 or on Windows XP Home Edition. Every additional language installed will require approximately 115 MB extra disk space for Windows XP, 45MB for Windows 2000; East Asian language support requires an additional 250 MB.

Microsoft Office also has its own Multilingual User Interface. (Office MUI)

Office and Windows MUI Packs: Links to Resources