Error 577: Windows cannot verify the digital signature for this file. A recent hardware or software change might have installed a filed that was signed incorrectly or damaged, or that might be malicious software from an unknown source.”
Solution 1 – Consider switching to a third-party antivirus software
Solution 2 – Change your registry
Solution 3 – Completely remove third-party antivirus tools
Solution 4 – Turn on Windows Defender from Notification Center
Solution 5 – Change the security permissions in your Registry
Solution 6 – Restart Security Center and Windows Defender service
How to fix Windows Defender error code 577?
What to do with Windows Defender Error 577? Uninstall Solution #1: Your external PC package. Always remember that if you uninstall a third-party antivirus package, Windows will most likely disable the built-in set of alerts automatically, i.e. Windows Defender.
Solution 2 – Change the key associated with the registry using Windows Defender
Decision #3. Restore the system implementation.
Why is Windows Defender not turning on?
You have installed other security software that is interfering with Defender.
The time and date pointing to your computer is not correct or even out of sync.
You are running a version that may affect older Windows 10 users.
A system build error has occurred on your device.
Windows Defender is disabled or disabled via Group Policy.
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How to configure Windows Defender in Windows 10?
Turn on Microsoft Defender. Select the antivirus launch menu.
In the search bar, type Group Policy.
Select Computer Configuration > Administrative Tools > Windows Component Templates > Microsoft Defender Antivirus.
Scroll down and select Turn off Microsoft Defender Antivirus.
Select Disabled, possibly Not Configured.
Select Apply > OK.
Why does Windows Defender not update?
If you are having problems, you can try the following: Restart your computer. …
Remove existing antivirus and antispyware software. …
Scan your new computer for malware. …
SFC scan. …
Clean start. …
Restart the Security Center service. …
Delete the conflicting registry entry. …
Enable Windows through Defender Group Policy.
Could not start Windows Defender service error 577?
Unable to start Windows. Windows Defender Service Error 577: Windows cannot verify all digital signatures for this file. A recent hardware or software change installed a file that was originally missigned, corrupted, or possibly malware from a fantastic unknown source.
Could not start Windows Defender error 577?
Failed to start Windows from Windows Defender Service Error 577: Windows cannot verify the digital signature on this file. A recent hardware and possibly software modification may have installed the latest badly signed or corrupted file, or it may be destructive software from an unknown source.
Can Windows Defender start Error 577?
Windows failed to focus on the Windows Defender service. Error 577: Windows cannot verify the digital signature required for this file. It is possible that a hardware and/or software modification was recently installed that you just mis-signed or corrupted, or it could be malware from an unknown location.
Why does Windows Defender keep getting error 577?
Another reason for Defender to fail is adware and some file corruption related to registry settings or trading. The best and cleanest way to fix Windows Defender Error 577 is to use a dedicated PC Health Advisor workstation optimizer. It will also scan you for issues and problems with the computer system.
What causes Windows Defender to say error code 577?
When creating Windows Defender, Windows may not be able to start the Windows Defender Network Inspection service on the local computer. Error code 577 can occur. What can cause this Windows Defender error 577? In most cases, problems with Windows Defender 577 occur on computers that have third-party antivirus software installed.
Why is there error 577 on Windows Defender?
Windows Defender Error 577 1 is one of those errors that prevents your website from activating antivirus on Windows 10 using Defender. Error: “The following error is 577: Windows cannot verify what the digital signature of this file looks like…”.
Why do I get error 577 when I start Windows Defender?
Error 577 usually appears when you are trying to start Windows and Windows Defender is preventing it from opening on your PC. Anyone can easily avoid such problems if you have a third-party antivirus that bypasses the default protection in Windows.
How do I fix Error 577?
How to solve the problem with finding Windows Defender error 577?
- Consider using third party antivirus software. …
- Change your registration. …Completely uninstall
- 3rd party antivirus tools. …
- Enable Windows Defender fully from the Action Center.
- Change… security permissions in the main registry.
- Restart… Security Center along with Windows Defender Service.

Vijay is a tech writer with years of experience in the Windows world. He’s seen it all – from simple problems to catastrophic system failures. He loves nothing more than helping people fix their PCs, and he’s always happy to share his wisdom with anyone who needs it.
When Vijay isn’t fixing Windows problems, he likes to spend time with his wife and two young children. He also enjoys reading, playing cricket, and watching Bollywood movies.