Считать значение REG_DWORD из реестра

uses
  Registry;

// Read REG_DWORD 
procedure TForm1.Button1Click(Sender: TObject);
var
  Reg: TRegistry;
  RegKey: DWORD;
  Key: string;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_USERS;
    Key := '.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings\URL History';
    if Reg.OpenKeyReadOnly(Key) then
    begin
      if Reg.ValueExists('DaysToKeep') then
      begin
        RegKey := Reg.ReadInteger('DaysToKeep');
        Reg.CloseKey;
        ShowMessage(IntToStr(RegKey));
      end;
    end;
  finally
    Reg.Free
  end;
end;


// Write REG_DWORD 
procedure TForm1.Button2Click(Sender: TObject);
var
  Reg: TRegistry;
  Key: string;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_USERS;
    Key := '.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings\URL History';
    if Reg.OpenKey(Key, True) then
    begin
      Reg.WriteInteger('DaysToKeep', 20);
      Reg.CloseKey;
    end;
  finally
    Reg.Free
  end;
end;