The issue for a lot of people is this: they want to buy an old computer for the kids etc, and somebody says, "I'll sell you one", and chances are Windows Update is on by default. And then lo and behold, it won't download critical updates because it fails validation etc. Why isn't there some kind of option for pay akin to Apple's Simple Finder, where Microsoft says something like , "You bought this secondhand, so you can't have the whole thing, with free copies of Office etc, but you can have this basic version with Works. We'll run you through a wizard where you can transfer your non-Microsoft files to an external drive. Connect the drive and press start when you're ready to begin."

Then your option buttons would be 'Start transferring and purchase Windows Basic'
or 'Later - I will run this PC without critical updates.'

Until Microsoft starts making biodegradable PCs or stops treating users like criminals they are going to have desertions in droves.