Today, I can't login the Window XP, because the keyboard seems not working. So, I can't input the longin password. However, keyboard works fine in Mac OS.
Any idea on how to fix it? Otherwise I need to re-install XP.

Really old versions of Input Remapper could cause this if the installation failed. If this happened with a new version I would need more information to be able to reproduce it, if it's Input Remappers fault at all.

Purchase/Borrow an external USB keyboard this will get round the login then you can run the remapper and set the keys as they should be.