procedure TForm1.CopyFileWithProgressBar1(Source, Destination: string); 

var 

  FromF, ToF: file of byte; 

  Buffer: array[0..4096] of char; 

  NumRead: integer; 

  FileLength: longint; 

begin 

  AssignFile(FromF, Source); 

  reset(FromF); 

  AssignFile(ToF, Destination); 

  rewrite(ToF); 

  FileLength := FileSize(FromF); 

  with Progressbar1 do 

  begin 

    Min := 0; 

    Max := FileLength; 

    while FileLength > 0 do 

    begin 

      BlockRead(FromF, Buffer[0], SizeOf(Buffer), NumRead); 

      FileLength := FileLength - NumRead; 

      BlockWrite(ToF, Buffer[0], NumRead); 

      Position := Position + NumRead; 

    end; 

    CloseFile(FromF); 

    CloseFile(ToF); 

  end; 

end; 

procedure TForm1.Button1Click(Sender: TObject); 

begin 

  CopyFileWithProgressBar1('c:\Welcome.exe', 'c:\temp\Welcome.exe');