You think that was a waste of bandwidth? My Win10 clean install (on a new PC) downloads the equivalent of itself *every day*.
Previously my monthly usage was around 30GB (some might consider that low in this modern era, but I don't do a lot of video watching). I was a bit miffed I had chosen my ISP's "unlimited" package over their cheaper capped option because I really struggled to get anywhere near the 40GB cap. Since installing the new PC with Win10 in February, last month's usage was 97GB without me even trying. This month I'm already at 96GB with a week to go until my next billing date. And that's *after* I switched off the peer-to-peer Windows Updates sharing which is on by default.
Next thing is to install something like ZoneAlam to try to find out where 4GB went in a 24 hour period when all I did was check email. Anyway who gets their Win10 by accident (I'm thinking grandparents who got the cheapest capped broadband because all they're doing is email and occasional Skype), is going to get horribly burned when they blow their cap in the first week.