My PC is running Windows 11.
A few weeks ago, a notification was displayed which said that the Windows Defender firewall was not started.
When trying to restore default Windows firewall settings through the control panel, I got either one or the other of the following errors:
Windows Defender Firewall can't change some of your settings.
Error code 0x8007045b
or:
[...]
Error code 0x800706d9
When looking at the Windows Defender firewall service, it appears that the service keeps trying to start then failing. The event viewer has plenty of messages saying that the firewall stopped due to an incorrect parameter.
I tried all the usual fixes for the Windows firewall but none worked. Besides, I found other problems in time, like the Windows Search button not working or the Start menu disappearing when I click on it, etc.
I downloaded an ISO image of Windows 11 and reinstalled while keeping data and applications. This got the firewall to work again but it failed on the first subsequent reboot and the other errors came back as well.
I ran many antivirus and anti rootkit programs. The only one which actually found something is Microsoft Safety Scanner which found this virus once with a full scan:
Trojan:Perl/Flooder.A!MTB
Now scans find nothing. Every time I reinstall Windows 11, the firewall gets back up and the other bugs disappear then everything fails again on the first reboot.
I would be very grateful if someone could provide advice on how to find the culprit and fix this.