LOL. So, instead of just replying to everyone separately, I thought I'd make a post. : D
EDIT: For someone reason, I can't get the LJ cut to work correctly, so I'm putting the images under LJ cuts. XD Sorry.
This is insanely simple, too. XD I use Vista, but I don't think it's that different for XP.
You would first need to go to your Control Panel and find Regional and Language Options.
Once there, click on the tab Keybaords and Languages. There should be a button that says, "Change keyboards..." If not, something similar to it.
After clicking on that, another small window should open up called Text Services and Input Langauges. I already added Japanese to mine. You should have only English or whatever language is your default.
Click on the Add button and scroll down the list of languages; find Japanese [Japan] and expand the Keyboard box. Checkmark the box beside Microsoft IME and only that box.
Click okay. Now Japanese should be added to your Installed Services list and should look like mine. Click okay. Two letters [EN] should appear on your task bar on the right.
If you left click on it, you can switch to Japanese or switch to the language bar. I prefer having it sit on my task bar, but that's just personal preference. I also minimize the amount of icons that appear. Of course, that has nothing to do with the way it runs. XD
Language Bar, it's ugly.
The icons that show up after switching to Japanese.
You can either manually switch between the languages, or you can create a hot key sequence by going to settings --> advanced key settings.
The best thing about this is that you don't need to use your keyboard like a Japanese keyboard. If you type k + u you'll get く. Basically, type the way you normally would. For instance:
Onegaishimasu! would become おねがいします!
Fantastic, right? XD
BTW, it will turn your hiragana into kanji if you press the spacebar after the word, and if you press it again it'll give you a list of kanji to choose from so you can get the correct one. I leave my settings on hiragana since it also uses katakana when it is necessary. Becareful when you are playing with it; you may accidentally switch it to Japaense Keyboard settings. XD The only way I know how to fix that is if you reset the Language bar.
: D I hope that helped everyone~
***********If you have another operating system...then I'm afraid I can't help you very much. XD However, I personally don't believe it should be that different. Just find your Keyboard and Language control center and see if anything is remotely simple. If not, I'm sure their are websites that can help you.