So all of a sudden, microsoft defender says it needs to scan my computer. This has never happened before. And, apparently I've joined microsoft spynet, an online community that helps me choose how to respond to spyware. I can decline if I want, but this is all new. WTF?

   

Open it.
Click on FULL scan instead of QUICK
Go to bed.

That's what it does. You have to scan your computer once in a while no matter what AV you use. You haven't, so its warning you its time.

   

Always fun the unwanted things that one of those updates can suddenly trigger.

   

But I have Kaspersky to do that. How come, after I'm not sure how many years I've owned this computer, all of a sudden it wants to scan it and make me part of an "online community?"

You're the wrong guy to ask, but is this Microsoft sneaking in the dreaded devil's program, win 10, bit by bit, or microsoft otherwise keeping tabs on me? (Paranoia strikes deep, into your heart it will creep.)

   

Remember that Microsoft is doing all of this for free and that their management and shareholders are among the most purely motivated and altruistic people in the world.

   

Oh Jeez, take off the tinfoil hat and look in your Programs list. Defender/MSE is a separate program from Windows7.
Did you actually start Kasperski and use the Scan screen recently? You still have to do that once in awhile, they don't magically do everything for you.
1) Google Adwcleaner and download it from BleepingComputer (only from there) and run it. Check and clean everything
2) Reboot and ControlPanel/Programs/uninstall
3) Pick ONE antivirus to keep and uninstall the others. MSoft one might show as Microsoft Security Essentials or Windows Defender.
Then update the one you keep and run it manually. If you're the type of computer user that gets hundreds of viruses at a time, keep Kasperski. It might find one extra the day before Defender does.
It's not spying - its telling you it needs to run, like the diskchecker does once in a while.

   

I didn't even know I had defender until I got rid of McAfee, which came installed. Then I started getting updates for Defender. But it never told me it needs to scan before, so it was a surprise when it popped up. Diskchecker also has never told me it needs to run, seems to just work in the background.

   

If your disk needs checking, it will pop up when you first boot Windows and gives you a chance to cancel it. If you want to run it yourself (do it if after a virus scan if your computer still seems deadly slow) open and elevated CMD prompt and type in "chkdsk /f". Say yes after that and it will run next reboot.

   

Windows defender also works in the background and scans your computer at 2 or 3 in the morning if you leave it on. If you are like me and shut it down when you aren't using it, then Defender will ask to scan your computer once in a while.

When you got rid of McAfee, you most likely got Defender through an update when you shut down your computer. If you don't have AV, Windows installs it automatically. Microsoft likes to install stuff you don't ask for.

No big conspiracy.

   

Just lots of little ones.

   

It's no longer a conspiracy when there is actual proof it's happening. Microsoft spies on you. They admit most of it, just not all of it. So does Apple, and Google, and Facebook . . .

Just an FYI.