I get a issue when using quiet mode, the problem is:
  I'm always prompted to select a language when installing"myapp.exe /quiet" if destination computer's language is not one of the languages myapp.exe supported.
Is there any way to DON‘T show this language selection window and make the whole installation real quiet? thanks in advance!

"myapp.exe /?" also prompt the language selection window, so seems windows installer detect current OS language whether is supported by myapp.exe first, then process /quiet option.