I have a macbook air with MacOS El capitan installed. After a reinstallation I have a problem. All my files and folders are in my external drive and most of them are written in Greek. In the terminal I can see all of them but in Finder nothing. I took my friends PC and all the files are there. If I rename any folder or file from Greek to English, I can see it in Finder and use the file. I also tried a new installation and installed Yosemite instead of El capitan and the same thing happens. Is there anything I can do to fix it because it's not possible to rename all my files.