How can I change the language of my XP operating system from English to Chinese?

I've already found a solution to input Chinese language, but how do I change the language of the entire operating system into Chinese? That is, the Start Button, names of folders, etc.

I would like to be able to type the chinese language on my emails?

My operating system is Windows vista. When I receive emails in chinese, I'm unable to read it. Simply I would like to read my emails that I receive that is in the chinese language and also be able to type my response in chinese if I need to.

How can I change the language of my XP operating system from English to Chinese?

I've already found a solution to input Chinese language, but how do I change the language of the entire operating system into Chinese? That is, the Start Button, names of folders, etc.

I would like to be able to type the chinese language on my emails?

My operating system is Windows vista. When I receive emails in chinese, I'm unable to read it. Simply I would like to read my emails that I receive that is in the chinese language and also be able to type my response in chinese if I need to.