I don't have 10, is defender on by default?

Wasn't Defender already included in Windows 7 and 8? It does a good enough job that I don't feel I need another anti-virus program. In Windows 10 there's also "SmartScreen", which may have a bigger impact since it's gotten quite difficult to install unsigned programs from outside of the Windows app store.

I have independent anti-virus software, so, i don't know if it turns itself on by default. It must have detected the independent antivirus as it's turned off. I have to think that's a good thing if it did run as on if it detects no antivirus software rather than to have nothing.

Yes Windows defender is turned on by default. If you turn it off in the settings screen for long time, it is turned on again by Windows.

At one US big box retailers all PCs come with a 6 month 'trial' version of Norton Antivirus. Comcast cable also offers Norton for free.

The problem is the education of the users. They click 'OK' on things they shouldn't and then the maleware has a forever 'free pass' to do anything it wants. Primary entry is websites visited and to a degree opening questionable attachments in webmail (poorly protected at the server and client level).

To me it's these apps and Windows giving the user too much freedom. Little has changed on the Windows end since Windows XP other than greater boot up infection hardening. Each new version upped the game in blocking, so yes, Windows 10 gets infected a LOT less than Windows 7. PCs setup by default using the administrator login with no password is seen too often, many times requested by the user. Some even demand it as 'xyz' app needs admin privileges or similar.

A cure I hope for is layperson/common man (idiot) mode in both OS and AV that DOES NOT ask for approval of anything not in it's database of known clean actions (website or app). Likelihood of it being offered? ZERO!

PS: I still am seeing a LOT of Windows 10 machines that were upgraded from Windows 7 with LOTS of maleware still present. So W10 doesn't cleanup on it's own prior to upgrading. Windows XP used to do an anemic try at cleanup on major service packs.

On the few rare occasions I have seen Windows Defender in action, I was quite impressed. Yes I'm going back as far as XP days. Maybe Win 98SE?

Those few events were primarily potential Malware, however one was an actual threat. Defender gave you two choices, and two choices only.

Kill it, or stare at a frozen PC for eternity. No other options were available. I later learned that if you has opted to hard reset the PC, you would have still been welcomed by the very same screen - FOREVER. That was under XP Pro.

Going back to the days when Norton and others originally came into being, I had a young relative at University who said the consensus of Uni opinion was the anti-virus people encouraged the development of viruses for their own commercial reasons.

Looking at the topic logically, the one corporation on the planet who has the biggest vested commercial interest in defending against a Virus has to be Microsoft simply to maintain the integrity of their OS. Malware seems to be on the back burner though.

I run Malwarebytes [Free] every so often, definitely right after having downloaded software, even after a custom install, and having declined the raft of browser add ons most people can never understand where they have come from.

Win 10 may (guarded may!) be the way future for more secure systems, but it will only be as secure as MS makes it. Their track record in that regard has been rather sketchy, even with the rollout of their free MS Security Essentials (XP to Win7) and Windows Defender (Vista to Win 10).

With Win10 being heavily vested in the "web of things" and synch of data across all platforms I suspect the target area has enlarged, not grown smaller, and the threat levels are higher than ever.