The English XP can write in traditional Chinese if you set up XP to do so.
You can do this from control panel> Regional and language options
If you mean now that you want all the menus, desktop and commands to be in
Chinese then you will have to install the
MUI (multi user interface) that includes Chinese, then you will be able to
switch between an ENG interface and a Chinese one.
You can find the MUI pack including chinese on the edonkey p2p network,
using a p2p client like emule since the MUI packages are not sold.
www.emule-project.net/