How do I know if I have fix windows firewall won't turn on or keeps turning off issues?

Common symptoms of fix windows firewall won't turn on or keeps turning off include: Windows Security shows "Firewall & network protection" as off for all profiles, Clicking "Turn on" in firewall settings does nothing, Error "Windows Defender Firewall can't change some of your settings" (Error code 0x6D9), Firewall service won't start — "Error 5: Access is denied", Third-party antivirus removed but firewall still won't re-enable, Firewall turns on but immediately turns itself back off.

Fix Fix Windows Firewall Won't Turn On or Keeps

Symptoms

You might be experiencing this problem if you notice:

•Windows Security shows "Firewall & network protection" as off for all profiles
•Clicking "Turn on" in firewall settings does nothing
•Error "Windows Defender Firewall can't change some of your settings" (Error code 0x6D9)
•Firewall service won't start — "Error 5: Access is denied"
•Third-party antivirus removed but firewall still won't re-enable
•Firewall turns on but immediately turns itself back off

Common Causes

⚠Windows Defender Firewall service (mpssvc) is disabled or stopped
⚠Base Filtering Engine (BFE) service is not running
⚠Third-party antivirus or firewall software disabled Windows Firewall and didn't re-enable it on uninstall
⚠Registry permissions on the firewall service key are corrupted
⚠Group Policy is forcing firewall off on managed PCs
⚠Malware intentionally disabled the firewall to allow network exploits

Solutions

Solution 1: Restart Firewall Services

1Open Services.msc as Administrator
2Find "Windows Defender Firewall" (mpssvc)
3Right-click → Properties → set Startup type to Automatic
4Click Start
5Also check "Base Filtering Engine" (BFE) — must be running
6Set BFE to Automatic and Start if stopped
7If either service fails to start, check the Dependencies tab
8Restart the computer and verify firewall is now enabled

Solution 2: Fix Firewall via Command Line

1Open Command Prompt as Administrator
2Reset firewall to defaults: netsh advfirewall reset
3Enable firewall for all profiles:
4netsh advfirewall set allprofiles state on
5If you get access denied, fix the service registry permissions:
6Open Registry Editor → navigate to HKLM\SYSTEM\CurrentControlSet\Services\mpssvc
7Right-click mpssvc → Permissions → ensure SYSTEM has Full Control
8Restart the computer and try enabling again

Solution 3: Remove Conflicting Software and Scan for Malware

1If a third-party firewall was recently uninstalled:
2Check for leftover services: look in Services.msc for remnants
3Use the vendor's official removal tool (Norton Removal Tool, McAfee MCPR, etc.)
4Run Windows Defender offline scan to check for malware:
5Settings → Windows Security → Virus & threat protection → Scan options → Microsoft Defender Offline scan
6After cleanup: sfc /scannow to repair system files
7Then: netsh advfirewall reset to restore defaults
8Verify firewall is enabled in Windows Security

FIXES THIS IN 5 MINUTES