Unicode characters suddenly start displaying as boxes in some applications [duplicate]

I had this issue. Stumbled upon the following setting in Windows 7 (professional):

 Control Panel --> All Control Panel Items --> Fonts --> Font settings

Hide fonts based on language settings was enabled. I disabled it and a big chunk of fonts appeared for me ... which allowed Eclipse to start displaying fonts that had been hidden.

In eclipse, I can now see all the nice UTF-8 characters I was using ... after I adjusted my fonts to allow it again. The original font that was assigned, 'Courier New' was displaying the items as boxes, as you described.

1. Go to "Control Panel" -> "Region and Language" -> "Administrative" -> "Change system locale..."
2. Change the locale to the one you're having problem with, and then change it back.

^{click to enlarge}

EDIT: Worked out a better solution that worked for me:

Make a file (any kind of file) on the Desktop that has some character of that language in the file name