Windows 10: Windows Defender Status: Unknown, Realtime protection cant be turned on and same as the...

It all happen sudden, just yesterday it was working fine the only thing i think that caused this is a trojan from a usb drive but windows defender already quaraitine it and for some reason i cant delete it, then the day after the windows defender became unknown, windows update is fine so as the scan, but the real time protection and the security intelligence is not working as supposed to be. I tried sfc scan, registry, scanning from malwarebytes and uninstall it, restared a few time, but none seems working. im panicking and i dont know what else to do, its not a group policy problem because you can click the on button on real time protection but it will only revert to off, same as others, checking updates in security intelligence do nothing, i wont get any updates and the status is unknown too.

:)

 

Windows Defender realtime scanning will not switch on - it detects another anti-virus product.

Windows Defender realtime scanning will not switch on, and the message suggests there is another anti-virus product present but if there is it does show up in Window 10 UI.

The long story is that I am troubleshooting a problem with application software. The manufacturer suggest removing Bitdefender because there product is incompatible. I thought I would give this a try, if only to element Bitdefender as a cause.

Firstly, I upgraded from Bitdefender 2016 to 2017 to see if that made a difference. The application still failed so I decided to try removal.

• I used the standard uninstall to remove Bitdefender 2017, rebooted but Windows Defender would not start realtime protection because another product was providing realtime protection
• I download the uninstall application for Bitdefender 2017, ran it then rebooted but Windows Defender would not start realtime protection because another product was providing realtime protection
• I checked the file system and all Bitdefender files have been deleted.
• I check the registry and found a couple of references to Bitdefender Wallet, then deleted these.
• I rebooted but Windows Defender would not start realtime protection because another product was providing realtime protection
• I reran the uninstall application for Bitdefender 2017 then rebooted but Windows Defender would not start realtime protection because another product was providing realtime protection.
  

I can find no traces of Bitdefender so I wonder why Windows Defender detects another anti-virus software. I've check other posts but couldn't find additional steps for uninstalling an anti-virus software. Any suggestions?

Moved from Windows 10

 

Windows defender realtime protection

Activate realtime protection on windows defender an cloud delivered

 

Realtime Protection

When I do Windows Defender update, the realtime protection turns off. Why?