How to Turn On or Off Microsoft Defender Antivirus in Windows 10  

thanks Brink, I do it regularly.
I just don't understand why Defender should take so much space.
it backs up scans, definitions and tons of other thigs.
just imagine Defender alone takes almost as much space as a WinXP installation.
something is going wrong there, just because drives are getting bigger we don't need to fill them with trash, do we!?

HI everyone
I am also getting the defender error and found this forum via M-soft and have followed all the advice but nothing has happened or changed.
http://answers.microsoft.com/en-us/p...8-07da52ab0502
This is what I have done;
I deleted my Norton using the removal tool and restarted the pc then
I tried your link
https://www.tenforums.com/tutorials/5...dows-10-a.html

I typed this into the run box HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
and it didn't work
so I did regedit and went to defender that way and again nothing happened
I have even tried "DWORD" in the run box and again nothing happened

what am I dong wrong?
Please keep it simple
I have windows 10 home installed

Thanks

Hi Brink
It was the windows defender and Norton issue and me panicing but it seems to have sorted it self out now
so happy days again :)
I did try your How to Turn On or Off Windows Defender in Windows 10 yesterday but nothing seemed to work and then this morning I still had that defender message again of the failed update after doing a windows update
but this afternoon everything is ok again


Thanks for getting back to me

I'm having a very similar problem and have read through the suggestions. As far as I know the only malware program I have in addition to Defender is Malwarebytes, which I have to manually activate because I have the free version which doesn't run in real time. It's basically a backup to Defender for scanning occasionally. I've both running on my system since upgrading to Windows 10 with no problem. This seems to have started since the last Windows update on March 8.


Now I'm getting the popup from Defender saying my computer is at risk. When I go into Defender to turn it on, it times out and fails to turn on. No amount of time I wait after restarting makes a difference. I've been on the computer for half an hour, and it's still off according to Defender. However, when I look at my security panel, it shows everything on. So...this is what I see:





Which screen is correct and what can I do about this? It's becoming very frustrating not knowing if my system is really at risk or not.

I've read about both the reg edit to disable the notification and to force Defender on, and also saw a post on Microsoft forums that says this is an issue with recent windows updates and a permissions glitch.

Brink said:

Hello Stormhawke, and welcome to Ten Forums. :)

It looks like you may just need to turn on real-time protection in Windows Defender.

https://www.tenforums.com/tutorials/3...dows-10-a.html

Thank you. I did read that post, and most of it seems irrelevant because every setting except for the program itself tells me Real Time Protection is already on (as shown in the picture in my above post). I don't show the Settings screen, but it also says WD is on. So I can't follow those steps anyway.

That only leaves option 4 in that post, which asks me to download something I don't know if I can trust. It still begs the question, how can the program be saying it's off, but my control panel and settings say it's on, and which is correct?