What is this "Windows new feature update"? [View all]

I've been getting a popup Window from Microsoft wanting me to update now or schedule a new feature update, but it doesn't tell me a thing about it except that it's a most wonderful thing. Not even a link to a site that tells what's in it. Two things worry me about it.

1. In Windows 10, Microsoft never asks me if I want an update. It just installs it. Sometimes it even reboots my computer without warning, throwing away anything I was working on, without even asking. (Unless it asked in the middle of the night when I was sleeping.) So it seems suspicious--either someone spoofing Microsoft or Microsoft wanting to foist something on me that I don't want.

2. Windows 10 Creator seems to be a big item these days, and one really negative thing that I've heard about it is that it won't let you run any software that you didn't download from the Microsoft store. That is something that I really really don't want because it would make thousands of dollars of software unusable and worthless. Apparently it would even refuse to run Java programs that I write for myself unless I put my Java app on the Windows store. So I'm worried that this wonderful "new features update" is really Windows 10 Creator and is going to essentially steal thousands of dollars from me and make most what I do on the computer impossible to do.

Anyone want to talk me down?