Windows Registry Editor Version 5.00

    [HKEY_CLASSES_ROOT\telnet]
    @="URL:Telnet Protocol"
    "EditFlags"=dword:00000002
    "URL Protocol"=""

    [HKEY_CLASSES_ROOT\telnet\DefaultIcon]
    @=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
      00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,75,00,72,00,\
      6c,00,2e,00,64,00,6c,00,6c,00,2c,00,30,00,00,00

    [HKEY_CLASSES_ROOT\telnet\shell]

    [HKEY_CLASSES_ROOT\telnet\shell\open]

    [HKEY_CLASSES_ROOT\telnet\shell\open\command]
    @="rundll32.exe url.dll,TelnetProtocolHandler %l"