Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

function GetTextFromFile(AFile: string; var Returnstring: string): Boolean;
 var
   FileStream: TFileStream;
 begin
   Result := False;
   if not FileExists(AFile) then Exit;
   FileStream := TFileStream.Create(AFile, fmOpenRead);
   try
     if FileStream.Size <> 0 then
     begin
       SetLength(Returnstring, FileStream.Size);
       FileStream.Read(Returnstring[1], FileStream.Size);
       Result := True;
     end;
   finally
     FileStream.Free;
   end;
 end;

 procedure TForm1.Button1Click(Sender: TObject);
 var
   s: string;
 begin
   if GetTextFromFile('c:\autoexec.bat', s) then
   begin
     ShowMessage(s);
     // Label1.caption := s; or assign the text to a Label 
    // Memo1.text := s;     or a memo 
  end;
 end;