Update: the "Easybits" affair
Freaking Lenovo,as part of the official Bluetooth driver package, installed those crapware games for me - with NO NOTIFICATION. No screen telling me it was happening, no opt-out, and no mention in the license.
Thus far, other than this crap (which probably did happen on all my installations for the last year since it's the same damn driver archive), I haven't noticed any problems going it alone with just Microsoft as my anti-virus and firewall friend.. But then... I suppose I wouldn't know, would I.