Well someone screwed up somewhere then, as it can't be MS that will let you fix a screwed up upgrade.
OH!, it probably doesn't actually work. :D
That's how it's usually done.
Seriously though, I have only had a small amount of time with 10 so far, so I'm sure there are some things to explore.
By the time I got through the settings that share your entire life with the world I didn't have much more patience for it at the time.