It all depends really. Many times games themselves will come with anti-cheat programs such as my most hated anti-cheat program PunkBuster, or Valve Anti-cheat which I like. Typically, unless you install an Anti-cheat program the game supports, there's no way to add one. nProtect GameGuard is pretty much just as bad as Punkbuster; rootkitting itself in your system, disabling your crap, and messing up your gaming experience.