Typing Hiragana, Katakana and Kanji on Keyboard

Is there somewhere I can go to download something to be able to type in Japanese with the keyboard? (Hiragana, Katakana, and Kanji)

http://www.coscom.co.jp/help3/inputjp/installime.html

I've tried that site demonic. It seems that everything I find about multi-language doesn't support my computer. My computer is HP but it's also a windows Vista.

こんにちは For vista, Access the start menu and click on control panel. Then click on "language, clock, keyboard". After that click on regional and language options. click on the keyboard and languages tab on the pop up menu. click change keyboard, click add... then scroll down till you get to the japanese selection. check the microsoft ime box, and click ok. On your task bar will be a new icon with an EN or a JP click on this to switch between english and japanese. I hope this helps.