Two posts in as many hours after a huge hiatus… :-S

Before reinstalling Windows yesterday, I turned off Real-Time Protection in Defender to perhaps speed the install process up a touch (LOL). After everything was updated, I was unable to turn it back on – it informed me I was “using other antivirus providers”!

I wondered if it was because I’d previously uninstalled the rather odd Microsoft Defender for Individuals thingy. I reinstalled it and it moaned that Defender’s real-time scanning was off, so I clicked on its prompt which opened the Security Center which then insisted my administrator (i.e. me) had disabled some settings!

I’ve never turned off such stuff in policy but I obediently checked the various Policies registry keys and all was well.

Next I put MalwareBytes back on; activated its trial so I could select to register it with Security Center; confirmed this had registered; and then unregistered it from there again before disabling the trial mode once more. Still no joy.

The main “Virus & Threat Protection” page in Security Center showed no problems, but note it has a less than obvious feature, highlighted below:

That showed the following:

Similarly, the Get-MpComputerStatus PowerShell cmdlet showed that Defender was running in “SxS Passive Mode“.

As per various onine suggestions, I tried to fix any possible WMI Repository corruption with:
winmgmt.exe /salvagerepository
But that found no issues. I was not willing to perform a /resetrepository as that can have quite a bit of fall-out.

Another command I tried which was referenced online was:
“c:\Program Files\Windows Defender\mpcmdrun.exe” -wdenable
It did not help either.

Then I remembered I had a few months ago tried a reinstall of SUPERAntiSpyware – an app which always struck me as a bit of an oddity, but which was a tool I had seen referenced more than once as something to use to be able to scan your machine with an alternate AV engine from time to time. I had uninstalled it a few minutes after installing it back then and didn’t really want to stick it back on. Fortunately, their site had a specialist Uninstall tool for it. I ran that and rebooted and the problem was fixed! :-D