How to disable windows update in Delphi

Try this code that I used in the past, to disable or enable Winodws update, I use the command line to get it. In a new project create a button and a memo on the button call the ChangeWindowsUpdate procedure.

I leave the example:

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
  private
    procedure ChangeWindowsUpdate;
    function GetDosOutput(CommandLine: string; Work: string = 'C:\'): string;
  public
    { Public declarations }
  end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ChangeWindowsUpdate;
end;

Function TForm1.GetDosOutput(CommandLine: string; Work: string = 'C:\'): string;
var SA: TSecurityAttributes;
    SI: TStartupInfo;
    PI: TProcessInformation;
    StdOutPipeRead, StdOutPipeWrite: THandle;
    WasOK: Boolean;
    Buffer: array[0..255] of AnsiChar;
    BytesRead: Cardinal;
    WorkDir: string;
    Handle: Boolean;
begin
  Result := '';
  with SA do
    begin
      nLength := SizeOf(SA);
      bInheritHandle := True;
      lpSecurityDescriptor := nil;
    end;
  CreatePipe(StdOutPipeRead, StdOutPipeWrite, @SA, 0);
  try
    with SI do
      begin
        FillChar(SI, SizeOf(SI), 0);
        cb := SizeOf(SI);
        dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
        wShowWindow := SW_HIDE;
        hStdInput := GetStdHandle(STD_INPUT_HANDLE); // don't redirect stdin
        hStdOutput := StdOutPipeWrite;
        hStdError := StdOutPipeWrite;
      end;
    WorkDir := Work;
    Handle := CreateProcess(nil, PChar('cmd.exe /C ' + CommandLine), nil, nil, True, 0, nil, PChar(WorkDir), SI, PI);
    CloseHandle(StdOutPipeWrite);
    if Handle then
      try
        repeat
          WasOK := ReadFile(StdOutPipeRead, Buffer, 255, BytesRead, nil);
          if BytesRead > 0 then
            begin
              Buffer[BytesRead] := #0;
              Result := Result + Buffer;
            end;
        until not WasOK or (BytesRead = 0);
        WaitForSingleObject(PI.hProcess, INFINITE);
      finally
        CloseHandle(PI.hThread);
        CloseHandle(PI.hProcess);
      end;
  finally
    CloseHandle(StdOutPipeRead);
  end;
end;

procedure TForm1.ChangeWindowsUpdate;
var APos: Integer;
    ALine, AState: String;
begin
  Memo1.Clear;
  //sc query wuauserv vai pegar o estado do windows update (parado,correr...)
  Memo1.Text := trim(GetDosOutput('sc query wuauserv'));
  Application.ProcessMessages;

  //vai ler a linha correspondente ao status
  if Memo1.Lines[2] <> '' then
    Begin
      ALine := Trim(AnsiUpperCase(Memo1.Lines[2]));    // exemplo da linha: "STATE              : 1  STOPPED"

      APos := Pos(': ', ALine);
      if (APos > 0) then Delete(ALine, 1, APos);
      APos := Pos('  ', ALine);
      if (APos > 0) then Delete(ALine, 1, APos);

      //vai ler o estado 
      AState := Trim(ALine);
      if (AState = 'RUNNING') then
        Begin
          //para o serviço
          Memo1.Lines.Add(GetDosOutput('sc stop wuauserv'));
          Sleep(5000);
          //desabilita o windows update
          Memo1.Lines.Add(GetDosOutput('sc config wuauserv start= disabled'));
          memo1.Lines.Add('--AutoUpdates Service Stopped--');
        End
      else if (AState = 'STOPPED')then
        Begin
          //habilita o windows update
          Memo1.Lines.Add(GetDosOutput('sc config wuauserv start= demand'));
          Sleep(1000);
          //inicia o serviço
          Memo1.Lines.Add(GetDosOutput('sc start wuauserv'));
          memo1.Lines.Add('--AutoUpdates Service Started--');
        End
      else memo1.Lines.Add('AutoUpdates Service Not Found');
    End;
end;

Any questions please let me know.

Windows update is a windows service, named wuauserv . By default, it gets stuck, and with the manual startup type. To deactivate, you have to change the startup type to desativado and for this, just run the command:

sc config wuauserv start= disabled

Passing this to delphi would look like this:

WinExec(PAnsiChar('cmd.exe /c sc config wuauserv start= disabled'), sw_hide );