Hello, I'm working under windows 7 with mingw. I have encountered some weird behaviour with unicode filenames. My program needs to be portable, and I'm using boost::filesystem (v 1.53) to handle the file paths. This has all been going well, until I needed to open files with unicode filenames. This is not about the content of the file, but the file's name/path. I tried the following: For testing I made a folder named C:\UnicodeTest\|????????|and I tried creating a file inside of it, by appending the file name test.txt to the boost wpath. For some reason the creation of the file fails. I'm using boost's fstreams and when I try to open the file, the failbit of the stream is set. Now the funny thing is, that when I append a foldername to the path instead, a call to create_directories() succeeds and creates the correct directory C:\UnicodeTest\|????????|\folder. I really don't understand why it won't work with a file. I have also posted my problem on stackoverflow. http://stackoverflow.com/questions/16875025/open-a-file-with-unicode-path No luck so far. This is the code I use: boost::filesystem::wpath path; // find the folder to test (There are no other folders in C:\UnicodeTest) boost::filesystem::wpath dirPath = "C:\\UnicodeTest"; vector<boost::filesystem::wpath> files; copy(boost::filesystem::directory_iterator(dirPath), boost::filesystem::directory_iterator(), back_inserter(files)); for(boost::filesystem::wpath &file : files) { if(boost::filesystem::is_directory(file)) { path = file; break; } } // create a path for the folder boost::filesystem::wpath folderPath = path / "folder"; // this works just fine boost::filesystem::create_directories(folderPath); // create a path for the file boost::filesystem::wpath filePath = path / "test.txt"; boost::filesystem::ofstream stream; // this fails stream.open(filePath); if(!stream) { cout << "failed to open file " << path << endl; } else { cout << "success" << endl; }