function TForm1.StartWithShell(Prog, par, Verz: string;
var hProcess: THandle): DWord;
var
  exInfo: TShellExecuteInfo;
begin
  hProcess := 0;
  FillChar(exInfo, Sizeof(exInfo), 0);
  with exInfo do
  begin
    cbSize:= Sizeof(exInfo);
    fMask := SEE_MASK_NOCLOSEPROCESS or SEE_MASK_FLAG_DDEWAIT;
    Wnd := 0;
    lpVerb:= 'open';
    lpParameters := PChar(par);
    lpFile:= Pchar(prog);
    nShow := SW_HIDE;
  end;
  Result := ERROR_SUCCESS;
  if ShellExecuteEx(@exInfo) then
    hProcess := exinfo.hProcess
  else
    Result := GetLastError;
end;

function TForm1.StartProgramm : Boolean;
var
  r, ExitCode: DWord;
  err: string;
  hProcess: THandle;
begin
  Result := False;
  r := StartWithShell('rar.exe', , 'c:\windows\system',
  hProcess);
  if r = ERROR_SUCCESS then
  begin
    repeat
      Application.ProcessMessages;
      GetExitCodeProcess(hProcess, ExitCode);
    until
      ExitCode <> STILL_ACTIVE;
    result := true;
  end
  else
  begin
    case r of
      ERROR_FILE_NOT_FOUND : err:='The specified file was not found.';
      ERROR_PATH_NOT_FOUND : err:='The specified path was not found.';
      ERROR_DDE_FAIL : err:='The DDE transaction failed.';
      ERROR_NO_ASSOCIATION : err:='There is no application associated ' +
      'with the given filename extension.';
      ERROR_ACCESS_DENIED : err:='Access denied';
      ERROR_DLL_NOT_FOUND : err:='DLL not found';
      ERROR_CANCELLED : err:='The function prompted the user for the ' +
      'location of the application, but the user cancelled the request.';
      ERROR_NOT_ENOUGH_MEMORY: err:='Not enough memory';
      ERROR_SHARING_VIOLATION: err:='A sharing violation occurred.';
      else
        err := 'Unknown';
    end;
    MessageDlg('Error: ' + err, mtError, [mbOk], 0);
  end;
end;