Here's a fun surprise: Microsoft allows driver vendors to ship arbitrary programs in addition to drivers. They will download and install these programs automatically. For instance, I bought some "gamer" mouse because it was the closest thing to an Intellimouse 3 I could find. Suddenly I have a \Program Files\Razer directory, and a popup on install telling me to register and do all this other stuff.

So if Lenovo was evil, they can just ship shit in their drivers, get it certified by MS, and have it distributed automatically by Windows Update driver install.