Hi Lighthouse Party,
Thank you for contacting Microsoft Community.
When windows firewall is not working and you try to manually turn it on, Error Code 0x6D9 might occur.
Few questions to get a clear picture of the issue
1. Is this issue specific to a particular application?
2. Are you facing any issues connecting to the internet?
3. Have you installed any third party antivirus or Security system on your computer?
4. Have you made any changes to the computer prior to this issue?
Follow the methods below and check if it helps:
Method 1:
To fix issues related to Windows Firewall you can also run a fixit- Diagnose and fix Windows Firewall service problems automatically.
http://support.microsoft.com/mats/windows_firewall_diagnostic/en-us?wa=wsignin1.0
Method 2:
Run a System File Checker scan to check for integrity violations.
Refer the article-
How to use the System File Checker tool to troubleshoot missing or corrupted
system files on Windows 7.
http://support.microsoft.com/kb/929833
Also follow the link below on
How do I fix network adapter problems? - If you can't connect to a network, there might be a problem with your network adapter.
http://windows.microsoft.com/en-us/windows/fix-network-adapter-problems#1TC=windows-7
Hope this helps. Get back to us for further assistance.