I have already isntalled Japanese language support on one of my PC's
(running Win XP Pro). I went to go do the exact same thing on another
PC, so I know I'm looking in the right place, as follows:

Control Panel
Regional & Language Options
Languages tab
Details button
Add button
Input Language dropdown box has many lanuages listed, but not the
Eastern Asian ones (Japanese, Chinese, etc)

This is Win XP Pro 2002 (no service packs installed)

Anyone have tips on how to get them to appear as choices there on this
machine? TIA