Ah thanks for the clarification. I wasn't sure if my cheap (Home Premium) version of W7 could switch over to Japanese. The old way of doing it (XP, Vista), if I remember correctly, was under the Keyboards & Languages Tab, which is pretty much empty on my copy of W7. So far I have not ran into any problems that AppLocale couldn't solve, but now I at least know what to try if I do run into problems.
Edit-Apparently my memory is terrible, the method has not changed at all. It always was the "Language for Non-Unicode" setting.