Stopping user creating Japanese folders

The setup is simple. All servers are either Windows 2000 or Windows NT in English. Half the desktop PC’s are either Windows 2000 or Windows NT Japanese.

The problem we have is if McAffee or Backup Exec has a problem with a folder or file which is named in Japanese, the error report displays not the Japanese name but garbage (like when you view a Japanese page with western encoding).

User training, requests and threats have not been of any use so now we are looking to lock down the function.

Anyone have an idea on how to stop people using double byte characters when saving files on the server?