Turning on Windows Defender after manual deinstallation of Trend Micro

After a manual deinstallation of Trend Micro Worry Free Business Security 9.0,
Windows Defender did not automatically see that it could turn on its antivirus component.

Done as prescribed here: https://success.trendmicro.com/solution/1056867-manually-uninstalling-the-security-agent-sa-in-worry-free-business-security-wfbs#collapseOne

It took me a while to find this solution, so here is a repost.

Found at https://answers.microsoft.com/en-us/windows/forum/windows8_1-winapps/error-577-when-i-attempt-to-turn-on-windows/4bf7ef42-7a50-4fe3-88ce-9f13cc2ab0f5

1. Press Win key + R. This will open Run.
2. Type “regedit” and hit enter.
3. Navigate to these keys:
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender
4. Change value of ‘DisableAntiSpyware’ and ‘DisableAntiVirus’ from ‘0’ to ‘1’.
5. After changing the values go to ‘C:\Program Files\Windows Defender’ and open ‘MSASCui.exe’ file.

If the gui is already open, close it first and then relaunch using MSASCui.exe.

Hope this helps you!