procedure TMainFrm.AddVarsToMemo(Sender: TObject);
var
  p: pChar;
begin
  Memo1.Lines.Clear;
  Memo1.WordWrap := false;
  p := GetEnvironmentStrings;
  while p^ <> #0 do
  begin
    Memo1.Lines.Add(StrPas(p));
    inc(p, lStrLen(p) + 1);
  end;
  FreeEnvironmentStrings(p);
end;