Como evitar que mis aplicaciones se "cuelguen"

[Gaim2205]

Sacado de las páginas de Torry

Código Delphi [-]
procedure TForm1.Cargar(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
  Cargar('c:\Windows\Welcome.exe', 'c:\temp\Welcome.exe');
end;