> # encoding: UTF-8
>
> fname = "ca_zufllige_luouk__ѧ٧ݧԧ_¿Գʵ.txt"
>
> system("notepad.exe #{fname}")
> IO.popen("notepad.exe #{fname}")
> Open3.popen3("notepad.exe #{fname}")
> ---------------------------------------
>
> I tried to open notepad from command line with same parameters and it works.

What is the output?  What if you surround the filename with quotes?
What about something like system("echo", "*") [1]

Thanks.

=r
[1] http://rubydoc.ruby-forum.com/doc/ruby-1.9.1-p129/classes/Kernel.html#M002830