You're thinking of the Windows Registry, aren't you? Mac OS X doesn't use a central database (which is essentially what the Registry is); instead, settings are stored in separate files for each program that needs one. These files are located in a variety of places: ~/Library/Preferences (the Preferences folder inside the Library folder inside your home folder), /Library/Preferences (the Preferences folder inside the Library folder inside the root of the hard drive), /private/etc (the etc folder inside the private folder inside the root of the hard drive; the private folder and the etc folder inside it are mostly reserved for low-level operating system things, and are therefore hidden by default), and there may be others I don't know about. Most preference files for applications are stored in .plist (property list) format, which can be viewed with the Property List Editor tool that comes with Xcode. Alternatively, you can open the .plist in a text editor - it's nothing more than specially formatted XML (eXtensible Markup Language).juhani said:Is there a thing called register or something in OS X like in Windows environment where all the stuff is written down?