"I have had to install new passwords onto sites I use regularly as they won't accept the old ones"
That would have nothing to do with Windows.
"Microsoft has promised a Windows Media Center replacement sometime in the future"
Wait, what? I know they promised a DVD app, but I don't recall this promise at all. Can you provide a...
You're thinking of "html5test" which isn't a speed test but an assessment of supported features.
What are you talking about? This is not-even-beta software. Microsoft doesn't want people bricking their phones and then whining about it.
The Windows Insider app's post about Windows Update warns against changing the registry, fyi.