Just for reference, the steps where:
- Open "Text Services and Input Languages"
- Right click on the Language bar → Settings...
OR - Control Panel → Region and Language → Keyboards and Languages → Change Keyboards...
- Click Add...
- Select the Keyboards you want to add. In my case:
- Chinese (Simplified, PRC) → Chinese (Simplified) - US Keyboard
- Japanese (Japan) → Japanese
- Korean (Korea) → Korean
- Click OK
- Click Apply
- Select and click Remove each language you don't want.
Update [16/03/2011]:
According to Sinsoul's comment below, the reason appears due to installed MS Office profiling tools. He suggested that you should also remove all unwanted languages from the language options in office profiling tools. Here's how:
Start -> Microsoft Office -> Microsoft Office Tools -> Microsoft Office 2007 Language Settings
On the right list (labeled "Enabled editing languages") select each language you don't want and click Remove.