I try to run WDO from the GUI, I get the UAC message "Do you want to allow this app to make changes to your device", and when I click Yes, it goes back to the Windows Defender GUI without running the scan.
Sometimes it won't run unless you first select Full scan (or Custom scan) and then select Windows Defender Offline scan before clicking on Scan now. It's an old issue that Microsoft hasn't bothered to fix.
I just ran a DISM and SFC scan. Corrupt files were found and repaired, but I still can't run the offline scan.
I just found a command line to run it from, but I believe these methods have changed in Win 10 1903.
Can anyone tell me if it is possible to run it from a command line? If so, when the command is?
It also looks like in the past, On win 7 & 8.1 it was able to run it from a bootable usb or cd. How about that possibility?
Start an Offline Scan with Windows Defender from PowerShell
Check the above link.
That may not solve the problem.
- Does Windows Defender online scan work ? If so, have you ran a full scan and may want to do a 3rd party AV scan.
- Are you receiving WD updates and is your system current with all regular updates ? (open Windows Security for the scan options and scroll down)
- If all fails, may want to try a System Restore or reset Windows.
I had the same problem a few weeks ago. Tried everything I could think of with no luck. Only thing that fixed the problem was a reinstall.
I found the subject on the net about that code 0x8004cc01. Here is the link to the Microsoft forum.
https://answers.microsoft.com/en-us/...9-9b2d9138233d
Looks like the problem has been left unresolved. I can confirm that the problem always happens,
even with perfectly intact systems. If Microsoft made Windows Defender Offline work well, it would be very useful.
Currently the Microsoft Defender tool, which should create a USB stick to scan at PC boot, does not work
for all three operating systems: Win7, Win8, Win10.
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