Fix Windows Defender Error Code 0x80508020

In the dialog box, Windows says that Windows Defender is subjected to an unexpected problem. The error code given was 0x80508020. As soon as I clicked Close in the error dialog, I received another error prompt:

This time, Windows said that it couldn’t turn on real-time protection followed by error code 0x800705b4. So in order to resolve both the errors, I start my troubleshooting steps from Registry Editor as it gives an instant fix. Eventually, I reached a saturation point, from where I fixed this errors for Windows Defender in few seconds. Here is how:

Defender Error 0x80508020, 0x800705b4

  1. Press Windows Key + R combination, type put Regedt32.exe in Run dialog box and hit Enter to open the Registry Editor.

  2. Navigate to the following location:

  3. In the right pane of this location, you’ll see DisableAntiSpyware named DWORD there having the Value data as 1. This DWORD is the root cause of both the errors which I received. So, double click on the DWORD to modify its Value data:

  4. In the above box, replace the Value data to 0 from 1. Click OK. Alternatively, you can delete the Windows Defender key from the left pane of the image shown in step 2. Finally, reboot the system and Windows Defender will start protecting your Windows 8 without any hitch.

Hope you find the fix useful!