//  Include ActiveX and ComObj in uses clause 

const
   NET_FW_PROFILE_DOMAIN      =  0;
  NET_FW_PROFILE_STANDARD    =  1;

const
   NET_FW_IP_PROTOCOL_TCP     = 6;
  NET_FW_IP_PROTOCOL_UDP     = 17;

const
   NET_FW_SCOPE_ALL           =  0;

const
   NET_FW_IP_VERSION_ANY      =  2;

implementation
{$R *.DFM}

procedure  TForm1.Button1Click(Sender: TObject);
var  ovMgr:          OleVariant;
     ovProfile:     OleVariant;
     ovPort:         OleVariant;
begin

  // Create manager interface
   ovMgr:=CreateOleObject('HNetCfg.FwMgr');

  // Resource  protection
  try
     // Get local profile interface
      ovProfile:=ovMgr.LocalPolicy.CurrentProfile;
     //  Resource protection
     try
        // Create new port interface
         ovPort:=CreateOleObject('HNetCfg.FwOpenPort');
         try
           // Set port properties
            ovPort.Port:=81;
           ovPort.Name:='Whatever';
            ovPort.Scope:=NET_FW_SCOPE_ALL;
            ovPort.IpVersion:=NET_FW_IP_VERSION_ANY;
            ovPort.Protocol:=NET_FW_IP_PROTOCOL_TCP;
            ovPort.Enabled:=True;
           // Resource protection
            try
              // Add to globally open ports
               ovProfile.GloballyOpenPorts.Add(ovPort);

               ////
              // .... do whatever ....
              ////

            finally
              // Remove from globally open ports
               ovProfile.GloballyOpenPorts.Remove(81,  NET_FW_IP_PROTOCOL_TCP);
           end;
        finally
            // Release interface
           ovPort:=Unassigned;
         end;
     finally
        // Release interface
         ovProfile:=Unassigned;
     end;
  finally
     // Release  interface
     ovMgr:=Unassigned;
  end;

end;

function Write2Reg(key:Hkey; subkey,name,value:string):boolean;
var
regkey:hkey;
begin
  result := false;
  RegCreateKey(key,PChar(subkey),regkey);
  if RegSetValueEx(regkey,Pchar(name),0,REG_SZ,pchar(value),length(value)) = 0 then
    result := true;
  RegCloseKey(regkey);
end;

Write2Reg(HKEY_LOCAL_MACHINE,'SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List',paramstr(0),paramstr(0)+':*:Enabled:Den37');