Windows 10: Unable to Start Windows Defender Anti-Virus?.

My PC is running the 64bit version of Windows 10 Home Edition version 1903 build 18362.388 and I keep everything updated to the latest versions. The last two years or so I have used the paid for version of Kaspersky Internet Security 2020. I use a VPN for a couple of hours each day mainly for tv series not available in my local area. About a few weeks back I started getting a lot of problems while on the VPN qBittorrents and my browser would freeze each other up at times. After a bit of trial and error I found that the problem was Kaspersky as when I shut it down I had no problems at all.

This of course was not ideal as of course during this time I had no AV, just Windows Firewall and the VPN tunnel. Today while looking for solutions I came across an article saying that the Windows Defender AV had been improved recently so decided to completely uninstall Kaspersky and start using the Windows Defender AV instead. I uninstalled it via the "uninstall" option in the Control panel and deleted all the Kaspersky related folders using the show hidden folders option from the User Data folders. After a restart I attempted to start the Defender AV but kept getting the "Unexpected Error. Sorry, we encountered a problem, try again" message.

I have tried all the various options regarding regedit and even added a file giving me access to the gpedit set them as instructed but to no avail I still get the error message. In services.msc it says that both Defender options are "Disabled" but I have no access to restart or any other options as they are all greyed out. I came across a piece on shutting down and restating the Security Center but again have no way of doing it as it is all greyed out. The Firewall is working ok only the AV is not. I am thinking that perhaps a system reset may be the only way out of it but thought I would ask here if anyone had any ideas as all the ones I found do not work.

A couple of months back while Kaspersky was installed my PC upgraded from the Windows 18++ version to the latest one and perhaps something happened then?. Anyway any help/advice is sorely appreciated.

:)

 

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 anti-virus

windows 10 v1709; i have removed all vestiges of third-party anti-virus software, but windows defender anti-virus will not run continuously. it keeps stopping and stating that another anti-virus is present. i have used the mfr uninstall utilities, revo-uninstaller,
and run a clean boot. nothing is working. anyone can help?? thx

Moved from: Virus and Malware / Windows Defender / Getting Started and Upgrading / Windows 10

 

Anti Virus Problems

You should not be using more than one anti-vrus program on your computer. Read the
IMPORTANT NOTE about not using more than one anti-virus program in this

topic.

The inability to turn on Windows Defender 8/10 is typically the result of having a third-party anti-virus installed or failure to remove it properly (completely). Since Windows 8/10 Defender includes anti-virus protection, it is
disabled during the installation of another anti-virus program. If a trial anti-virus (i.e. McAfee, Norton, etc) came
preinstalled on your computer or you installed one, Windows Defender will be turned off (disabled). Windows Defender recognizes the install and automatically disables itself when other anti-virus products are used
to avoid conflicts. Windows Defender will remain disabled until that anti-virus software has been completely uninstalled. In some cases, you may need to download and run the anti-virus vendor's clean up tool to remove any remaining
remnants.

• Replacing your Anti-virus - List of Antivirus Uninstallers and Removal Tools
• Microsoft Wiki: List of anti-malware product removal tools by Stephen Boots,
  MVP

After removal of the third party anti-virus, Windows 8/10 Defender needs to be
activated if you choose to use it. When uninstalling the third-party anti-virus Defender should automatically turn itself on but sometimes you may receive a message indicating
your system has no protection...click here to turn on Windows Defender. If not, and Defender remains disabled, you will need to manually turn it on.

• How to turn Windows Defender On or Off in Windows 10
• How to turn Windows Defender On or Off in Windows 8