function GetVersion(FileName: string; var Major, Minor, Release, Build: DWORD): DWORD;
var
  VerInfoSize, VerValueSize, Dummy: DWord;
  VerInfo : Pointer;
  VerValue : PVSFixedFileInfo;
  err : DWORD;
begin
  err := 0;
  VerInfoSize := GetFileVersionInfoSize(PChar(FileName), Dummy);
  if VerInfoSize <> 0 then
  begin
    GetMem(VerInfo, VerInfoSize);
    try
      GetFileVersionInfo(PChar(FileName), 0, VerInfoSize, VerInfo);
      if VerInfo <> nil then
      begin
        if VerQueryValue(VerInfo, '\', Pointer(VerValue), VerValueSize) then
        begin
          with VerValue^ do
          begin
            Major := dwFileVersionMS shr 16;
            Minor := dwFileVersionMS and $FFFF;
            Release := dwFileVersionLS shr 16;
            Build := dwFileVersionLS and $FFFF;
          end;
        end
        else
          err := GetLastError;
      end;
    finally
      FreeMem(VerInfo, VerInfoSize);
    end;
  end
  else
    err := GetLastError;
  result := err;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Major, Minor, Release, Build: DWORD;
  err: DWORD;
  s: String;
begin
  err := GetVersion(ParamStr(0), Major, Minor, Release, Build);
  if err <> 0 then
    s := SysErrorMessage(err)
  else
    s := Format('%d.%d.%d.%d', [major, Minor, Release, Build]);
  ShowMessage(s);
end;