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.”
1. Consider switching to a third-party antivirus software
2. Change your registry
3. Completely remove third-party antivirus tools
4. Turn on Windows Defender from Notification Center
5. Change the security permissions in your Registry
6. Restart Security Center and Windows Defender service
7. Create a new user account
Could not start Windows Defender service error 577?
Windows failed to start Windows Service Defender, error 577: Windows should not verify the digital signature for this skill file. A recent hardware or application change may have resulted in the installation of a missigned or corrupted computer file that could be malware from an unknown source.
Could not start Windows Defender error 577?
Windows may not start the Windows Defender service. Error 577: Windows cannot verify all digital signatures for this file. A recent hardware or software change likely installed a file that is still incorrectly signed, corrupted, or may be malware from a great unknown source.
Can Windows Defender start Error 577?
Windows couldn’t think of Windows Defender Service Error 577: Windows was having problems verifying the digital signature on this file. A recent hardware or tool change may have installed a poorly signed, malicious, or possibly malicious computer program from an unknown source.
Why does Windows Defender keep getting error 577?
Another reason why Defender gets close is malware that corrupts some files or changes registry settings. The best and easiest way to fix Windows Defender error 577 is to use a dedicated PC Health Advisor computer optimizer. It scans your laptop for errors and system issues.
What causes Windows Defender to say error code 577?
You may encounter the “Windows Defender Network Inspection Service on Local Computer cannot serve Windows” error with software error 577 while running Windows Defender. What can cause Windows Defender Error 577? In most cases, Windows Defender Error 577 occurs on a computer that has third-party antivirus software installed.
Why is there error 577 on Windows Defender?
Windows Defender related error 577 is one of those errors where you can’t enable Windows Antivirus 10 with Defender. Error: “Error 577: Windows cannot verify the digital signature of this file..”
Why do I get error 577 when I start Windows Defender?
Error 577 usually occurs when you try to launch Window Defender and prevent it from opening directly on your PC. You will certainly avoid such traps if you purchase a third-party antivirus that significantly bypasses the standard Windows protection.
How do I fix Error 577?
How to fix Windows Defender Error Switching 577?
- Consider any third party antivirus software. …
- Edit your own ad.
- Completely… Uninstall third-party PC tools. …
- Turn on Windows Defender from the Action Center. … change the
- security permissions in your registry. …
- Restart the Security Center and the 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.