I can't remember what exactly you need to do for specific programs. I just set up everything. For XP (you'll probably need your CD)...
1. CONTROL PANEL > REGIONAL AND LANGAUGE OPTIONS > LANGUAGES >INSTALL FILES FOR EAST ASIAN LANGAUGES
2. CONTROL PANEL > REGIONAL AND LANGAUGE OPTIONS > LANGUAGES > ADVANCED > CODE PAGE CONVERSION TABLES > tick everything Japanese... or just tick all of them, which will probably be easier.
3. Pickup the IME, which is always useful, even if just searching for random things on Amazon...
http://www.microsoft.com/downloads/deta ... layLang=en
Speaking of the IME, are there any keyboard shortcuts to switch between Japanese and English, and also katakana/hiragana, etc? No biggie, I just find keyboard shortcuts a little faster, rather than fiddling around with menus in the taskbar.