I got a laptop ( a used one) with chinese language and i need to change it back to English language which is what i understand. How do i do this.

i have a toshiba m825 laptop. it is full chinese language. i want to have it in english. i don't understand any chinese. how can i install english language pack?
it is windows vista home basic.

I got a laptop ( a used one) with chinese language and i need to change it back to English language which is what i understand. How do i do this.