If anybody wants to know: current flac.exe is not compatible with Windows 2000. The only reason for this is the following line from get_utf8_argv() function from src/share/win_utf8_io/win_utf8_io.c: if (wgetmainargs(&wargc, &wargv, &wenv, 1, &i) != 0) return 1; Windows 2000 has slightly older version of msvcrt.dll, and this check always fails. I found an explanation about it here: http://lists.gnu.org/archive/html/tinycc-devel/2014-11/msg00005.html (it's not something that should be fixed, of course)