Antivirus programs? When was the last time you tried Windows, the mid-00s?
Anyway, it's not random print services causing CPU overhead, that's old timey stuff. In this case it's being RAM heavy in a RAM-limited scenario and, from their testing, Lenovo being really terrible at keeping their AMD Windows drivers updated. As part of the test they manually switched to an ASUS version of newer AMD drivers and saw significant boosts in some games.
Modern graphics drivers are a mess of per-game features and optimizations. Different manufacturers keeping things at different levels of currency is a nontrivial issue and why some of this benchmarking is hard and throwing five random games at the problem doesn't fully answer the question.