Well, this happens to me very often previously before my colleague told me to put one text file on my desktop with Chinese characters.
True enough, when I got hold of my new laptop, without this chinese text file, even when I type chinese characters, it will show squares instead of displaying the actual chinese characters I keyed. Remembering the solution, I did as mention earlier. Restart my laptop, voila, it works!
Not sure why I have to do this, but perhaps someone out there know how to solve this? Else I will just stick to this solution!