Being able to type Japanese ideograms on an English version of Windows XP is easy. First, you’ll need to install East Asian language support. For this, go to control panel -> Regional and Language options -> Languages tab. Then tick the box for “install files for East Asian Languages.” You’ll probably need your XP CD for this.
Then, under that same tab slightly above the East Asian languages option is a box that says “details.” Click that, and then click the “add” button. Select Japanese on both pull down menus, click ok, and then you are done. XP home edition may be different. This does not change the language for the XP operating system, only the input, so don’t worry about getting your pc stuck in Japanese.
This adds the language bar to Windows XP (if you didn’t have it already). If a window does not display the language bar (such as in an IM program), you can change the language option and then go back to the window to type in Japanese. Shift + Alt. by default allows you to switch between languages. You can have the language bar at the top of the screen or minimized at the bottom right. Under input mode you can change between direct input (romaji), hiragana, katakana, etc. You’ll need to understand Japanese syllables in order to be able to type correctly; some Roman character combinations don’t exist in the Japanese language. Typing in ‘h’ and then ‘i’ will give the hiragana for ‘hi’ in hiragana mode (ひ). Pressing the space key allows you to cycle through the kanji for that ideogram (i.e. fire: 火), and you can then press ‘enter’ to continue typing. You can just press enter to move on without selecting a kanji. Foreign words will be written in katakana by default, usually.