Some third-party tools bundle outdated or broken versions of WinDivert. You can manually install the latest signed version from the official source.
Even after applying multiple fixes, the error may return. The top culprit is Fast Startup combined with a leftover driver service entry in the registry.
To permanently resolve:
Remove WinDivert service:
sc delete WinDivert1.4
(the version number may vary)
Reboot, then reinstall your tool.
After these steps, the dreaded message “WinDivert driver cannot be installed – you must restart your computer” will no longer appear. Some third-party tools bundle outdated or broken versions
If the error implies the driver cannot be loaded (sometimes confused with "cannot be installed"), you may need to allow unsigned or test-signed drivers, though modern official builds of WinDivert are usually signed.