How did Windows 10 get on here??

You turn on your Windows 7 or 8 machine one morning, expecting to quickly check your email before you head off to a meeting and.... huh?

It's installing WINDOWS 10?

How did that happen? You didn't WANT Windows 10 on there!

Probably:
[see also: http://www.pcgamer.com/windows-10-is-sneaking-onto-new-windows-7-and-8-installs-without-permission/ ]

1. You have "Auto update" turned on. (Normally, this is important because it allows Microsoft to keep your operating system as safe as possible.)

2. Microsoft has decided that Windows 10 is a "recommended update" so... since you have Auto update on...it sends it to you.

3. It downloads onto your computer (while you are online doing other things) and you may not even notice.

4. Eventually, it asks you if you want to install it. You often click "no".

5. After a number of "No" clicks, the "no" button disappears. (If you click the  More Info button, you may still have a way to say "no." BUT, most of us don't know that.... so we shrug and click it shut or click "ok.)

6. You've just agreed to have Win 10 installed.

7. It starts to install (a window pops up). It takes a (long-ish) while. Mine took about 45 minutes. During this time, I could do nothing with the computer.

8. When it is done installing Windows 10, your computer's desktop will look different. Your various icons may... or may  not... be there. Your programs may or may not work. Your printer, scanner, keyboard, monitor, etc. may or may not work. (Probably will, but Windows does not guarantee it.)

9. If today is your lucky day, all your data (your photos, documents, budget information, database) will still be there and usable.

And, your programs (games, photo editing software, security and anti-virus software, music software) will still work. 

10. You will want to budget some time to fiddle around and learn Windows 10. It looks different and acts different. 

There are many "how to" websites to help you.

11. You should secure Win 10 by making some basic security changes (see this article for more on this.)

and 

12. If you REALLY DO NOT WANT Windows 10 once it is finished installing and for the next 30 days ONLY, you can uninstall it and revert back to your "old" operating system. 

Here's how>> http://www.howtogeek.com/220723/how-to-uninstall-windows-10-and-downgrade-to-windows-7-or-8.1/


Of course, this will not stop Microsoft from again trying to install Windows 10.... but it will get you back your "old"operating system for a while. If you do this, you should then turn OFF "auto update" and do those updates manually after checking to make sure they are not going to be Windows 10 again.