Windows defender will not turn on

Liefr used Ask the Experts™
I get error 577 when trying to start the Windows defender services. This is 'Windows cannot verify the digital signature for this file.' it goes on for a bit.
I am using windows 10 latest updates.

I have no other anti-virus installed. I had Superantispyware installed but removed it trying to solve this problem. Windows firewall is active.
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John TsioumprisSoftware & Systems Engineer
It seems that this is a bad registry error
Check this:
Navigate to the following keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender
and change
'DisableAntiSpyware'  from '0' to '1'.
'DisableAntiVirus' from '0' to '1'.
retry again....possibly needs a reboot after editing registry
Kundan GuptaSenior Administrator
Press Windows key + X key.
Select Control Panel => Programs => Programs and Features.
Look for the AV, highlight it and click Uninstall.
Reboot and try to launch Win Defender.
RaminTechnical Advisor
1.Press Windows key + X key.
2.Click Command Prompt (Admin).
3.Type ‘sfc /scannow’ without the quotation marks and hit Enter.
4.Wait until the process completes.
 If some defective files have been detected but could not be restored, type: dism /Online /Cleanup-Image /RestoreHealth  press Enter (this step requires an active Internet connection to access Microsoft servers).
 Wait for the procedure to finish and repeat step 3.
5.Exit Command prompt, reboot the PC.
I have tried all of these suggestions and none of them have produced a desired result. I am using a third party AV. Thanks for trying.


The suggestions were not effective in my case.

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