Supposedly it's due to the XP-style Windows Update utility they've integrated (downloads "fixes" and autoinstalls them, unless you change the settings) but I wouldn't put it past them to do something scummy like that.
I don't have much to fear from them - I've got legit licenses for everything - but if it gets hairy, I'm wipin' everything and moving to Linux. The main problem is getting my wife comfortable with it. I'm already using Linux for most of my work, just using Windows to keep in practice for my job...