Speaking of badware: last week I found Mac Afee installed on the laptop of a relative that I manage. I assured me that he had not installed it himself (I had not installed anything actually). Could it have come from windows updates ?
No, Windows Update doesn't distribute third party software. And even if it did, MSE is technically a competitor to McAfee so there wouldn't really be a solid reason to distribute it.
Your relative probably installed something and pressed "Next" through all the dialogs including the ones asking if they want to install super helpful bundled software.
McAfee comes packaged in the installation of some other software, e.g., Java, where it can easily be installed by mistake if you aren't paying attention.
