How do I fix error code 0x6d9?

Here’s how to do it:

1. Open up the Start Menu, type cmd, right-click on the first result and select Run as an Administrator.
2. After, type in the following commands one by one:
3. netsh advfirewall reset net start mpsdrv net start mpssvc net start bfe regsvr32 firewallapi.dll Resetting Windows Firewall.

How do I fix firewall not opening?

To reset the Windows Firewall to its default settings, do the following:

1. Open Control Panel.
2. Click on System and Security.
3. Click on Windows Firewall.
4. On the left pane, click the Restore defaults link.
5. Click the Restore defaults button.
6. Click Yes to confirm.