Не найдено тело функции setrootkey при работе с реестром

TRegistry *Reg=new TRegistry;
Reg->RootKey = HKEY_CURRENT_USER;
Reg->OpenKey("Software\\blabla\\Project\\Users",true ) ;

Unresolved external '__fastcall System::Win::Registry::TRegistry::SetRootKey(void *)' referenced from UNIT21.OBJ

TRegistry *Reg=new TRegistry;
\\Reg->RootKey = HKEY_CURRENT_USER;
Reg->OpenKey("HKEY_CURRENT_USER\\Software\\blabla\\Project\\Users",true ) ;

void __fastcall TForm1::Button2Click(TObject *Sender)
{
   HKEY tempKey;
   HRESULT Status = RegCreateKeyEx(
                     HKEY_CURRENT_USER,
                     "Software\\blabla\\Project\\Users",
                     0, "" ,
                     REG_OPTION_NON_VOLATILE,
                     KEY_ALL_ACCESS, 0, &tempKey, 0);
   if SUCCEEDED(Status) ShowMessage("Key create");
}

void __fastcall TForm1::Button3Click(TObject *Sender)
{
   HRESULT hr = RegOpenKey(HKEY_CURRENT_USER,
    "Software\\blabla\\Project\\Users",
     &tempKey);
   if SUCCEEDED(hr)
   {
     char *buffer = "Victoria";
     RegSetValueExA(tempKey,"Parametr1", 0, REG_SZ,
        buffer,strlen(buffer));
     ShowMessage("Key opened");
   }
}