 the OS may not be correct, and you want
        to try to fix it, you can try this.</p>
    
    <p>Open a commandline window and enter <code>assoc .jar</code> which should output
        <code>.jar=jarfile</code> and enter <code>ftype jarfile</code> which should
        output something like <code>"C:\Program Files\Java\jre7\bin\javaw.exe" -jar "%1" %*</code>
        (see also <a href="http://stackoverflow.com/questions/10875839/jar-file-keeps-giving-me-could-not-find-the-main-class-program-will-exit">
  