WinDivert uses a test-signed certificate. On 64-bit Windows with Secure Boot enabled, driver signature enforcement may block unsigned or self-signed kernel drivers, causing the installation to fail.

: If you see "Error 577," Windows is rejecting the driver's signature. Updating Windows often resolves this by refreshing root certificates.

and run these commands to force-remove the existing driver service: sc stop windivert sc delete windivert Note: If you are using version 1.0, the service name may be WinDivert1.0 Clean the Registry

Windows 10 and 11 have a feature called (part of Core Isolation) that blocks drivers it doesn't recognize. If your WinDivert version is older or unsigned, Windows will block it silently.