Windows 10: defender won't start

A friend asked me to check his antivirus, defender will not start no matter what I do, I have followed many suggestions as to how to get it to start, none worked. He had newest version 1709, he did have webroot and took it out so defender should start, it will not, it says sorry we have a problem please try again, trying again does nothing.

:)

 

Windows Defender

My Windows Defender won't start, what can info? I tried to start it but it won't start.

 

Windows Defender not running on Windows 10

I'm trying to run Windows Defender on my Windows 10 Home machine, but it won't start.

Whenever I try to start defender (by going to settings->update & security->Windows Defender) the settings screens closes. If I search for defender I also get a "desktop app" as a result, but it won't run either.

Is there a way to get Defender to work, or is there a way to reinstall Defender on Windows 10.

 

Turn On or Off Windows Defender in Windows 10 Security System Tutorials

You can also try to run this as admin:

[Batch] Windows Defender Enable - Pastebin.com

 

he did have webroot and took it out

Did he use an uninstall tool for Webroot or the Windows Control Panel uninstall ? A cursory glance while trying to find a link indicates Webroot may be difficult to uninstall which may be effecting Defender.

If the links provided above by TO do not work, may want to research and find an uninstall tool (if not previously used). If necessary, may want to download RevoUninstaller. Also, manually check the registry (regedit) and file explorer (folders) to delete any Webroot entries.

Final option would be to reset or reinstall Win10.

Reset Windows 10

 

If you didn't use an uninstaller from Webroot there may be fragments left in your system that are preventing Defender from starting. You can d/l the removal tool & run it if you haven't done that yet.

 

Hi, when did your friend's defender start acting up?