C:\Windows\system32\FNTCACHE.DAT
and restart, your problem should be solved.
Windows XP had a “supplemental language support” section under Regional and Language options. You had to select them and perform the installation (which required the CD and was annoying) if you wanted to work with Asian languages. This was removed with Vista and support for these languages came by default. Windows 7 turns out to be a little different, however.
I usually do not find what Microsoft chooses to hide from the UI very useful. Why do I need to hit the alt key to see the file menu for example? This started with Internet Explorer and seems to be applied to other apps as well, including Windows Explorer. All of a sudden, the menu disappeared… Yes, it provides a little more space on the screen, but that space is not very useful as menu bar is not located at direct eye sight anyway. Does anybody browse the Internet full screen? No.
Lets get back to the Font issue. I launched an html document with Japanese strings in Notepad and was presented with a bunch of boxes! Boxes are how Windows expresses “I don’t know how to display this character”. I went to Format > Font to pick a font which supports Japanese script but none existed! Ah, must be the newest victim of Microsoft hiding team…
Windows 7 hides fonts depending on your language settings. Go to Control panel > Fonts > Font settings and uncheck “Hide fonts based on language settings”
Hiding the fonts is supposed to simplify the font selection in applications. I am not sure which applications are targeted for this but Notepad is definitely not one of them. The font selection dialog has always been and is still far from being user friendly and having 80 fonts instead of 200 doesn’t really provide any improvement.
I picked MS Minco for the font and Japanese for the script and there we go. No more boxes!
REFERENCES
http://superuser.com/questions/372928/windows-7-japanese-not-displaying-in-windows
http://www.emreakkas.com/windows-tips/how-to-enable-hidden-fonts-in-windows-7
http://mangahelpers.com/forum/showthread.php/3709-How-To-Enable-Japanese-Language-Windows