The laptop is working, but in Japanese Language

Hi Experts,
I just bought a second hand Toshiba laptop from eBay which I like to give to my little sister. When I finally received the laptop, from its package to the laptop and with its accessories, I am to say that it is well maintained by the previous owner.
Checking the insides, it is booting up fine, and by the looks of it, it must be running on Vista. Problem now is, the navigation are all in Japanese Language. And I do not understand a thing. I just know where to click the Start button. Please help on how can I revert it to English?
