/*
             *修改預設瀏覽器
             */
            //瀏覽器路徑
            string exePath = @"F:\firefox\firefox.exe";
            //登錄檔項
            string reg = @"http\shell\open\command";
            string nameReg = @"http\shell\open\ddeexec\Application";

            RegistryKey key = null;
            try
            {
                key = Registry.ClassesRoot.OpenSubKey(reg, true);
                if (key != null)
                {
                    key.SetValue("", string.Format("\"{0}\" -- \"%1\"", exePath));
                    key.Close();

                    key = Registry.ClassesRoot.OpenSubKey(nameReg, true);
                    if (key != null)
                    {
                        key.SetValue("", Path.GetFileNameWithoutExtension(exePath));
                        key.Close();
                    }
                }
            }
            catch (Exception)
            {
                key.Close();
            }