I went to go install a trustworthy program today and Windows Defender was 'removing malware' AKA the files (they were not malicious) and now I am attempting to disable my protection or add an exclusion but all these options are greyed out. I am currently running Windows 10 version 1511 OS build 10.586.318 .
Sounds like a malicious file or some sort of incompatibility - what file were you trying to install? Can you scan it at virustotal.com to verify it is not malicious?
Do you have a System Restore point you can use to go back to before the install was attempted?
You need to be logged into an account with Administrator access to make those changes
If Defender removed those files, then I would be wary of them. Granted, it could be a false positive, but in most cases there's a good reason the file was flagged for removal.
Did you have the same problem accessing the settings before the installation? If your firewall settings are having problems after trying to install this file, that should be a red flag. Malware operates by disabling protective services & the firewall is one of those it disables.
If you are logged in as admin & you are still having problems with the firewall, it would be a good idea to run a scan with Malwarebytes, AdwCleaner & TDSSKiller to assure nothing got onto your system & is attempting to disable security programs.
Also, if you opt to do a system restore after a possible malware infection, do not use the 1st restore point, roll back to the 2nd or 3rd point. Some malware will embed itself into the 1st restore point, so rolling back to that leaves the malware intact on the system.
Firstly, this software is from a reputable company, Lockheed Martin - Prepar3D , and it is know that it causes Windows Defender to 'detect' some sort of malware. I can assure you it is not. Secondly, I have run several virus scans including that listed above by simrick and with other software such as malwarebytes, adwcleaner, etc and I have found nothing. Finally, yes I do have admin access and I have it enabled on my account and no luck it still locks me out of these settings.
You might want to run an SFC to see if something is corrupted in the Win files.
SFC Command - Run in Windows 10 - Windows 10 Forums
Note
Sometimes it may take running the sfc /scannow command up to 3 times with Fast Startup turned off and restarting the computer after each time to completely fix everything that it's able to.
Option Three: (recommended)
Something else you might want to try is to turn off Defender & then turn it back on. Or turn it off, reboot, then turn it back on & reboot. I've seen instances of that action restoring the functionality.
Windows Defender - Turn On or Off in Windows 10 - Windows 10 Forums
Run CMD as admin and copy/paste:
reg delete "HKLM\Software\Policies\Microsoft\Windows Defender" /f
Solved! A quick SFC scan and look at the logs revealed that some aspects of Windows Defender had been moved (my own doing when moving items off my SSD) then followed by a quick restart and I was able to change all my Windows defender settings. Thank you mate.You might want to run an SFC to see if something is corrupted in the Win files.
SFC Command - Run in Windows 10 - Windows 10 Forums
Sometimes it may take running the sfc /scannow command up to 3 times with Fast Startup turned off and restarting the computer after each time to completely fix everything that it's able to.
Option Three: (recommended)
Something else you might want to try is to turn off Defender & then turn it back on. Or turn it off, reboot, then turn it back on & reboot. I've seen instances of that action restoring the functionality.
Windows Defender - Turn On or Off in Windows 10 - Windows 10 Forums
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