13 reasons why Windows Firewall doesn’t work in Windows 10 (and how to fix it)

If your Windows Firewall doesn’t work in Windows 10, the most common causes are stopped or conflicting services, third‑party security software, corrupted settings or system files, incorrect network profiles, or Group Policy/registry overrides. This article lists the 13 most frequent reasons this happens and gives clear, step‑by‑step fixes so you can restore firewall protection quickly.

You’ll learn how to check services, reset configurations, repair system files, remove conflicts, and test the firewall so it reliably blocks or allows traffic as intended.

Key Takeaway

Start by ensuring the firewall and its required services are running, then eliminate conflicts from third‑party security software and repair corrupt system/configuration files—these steps resolve the vast majority of Windows Firewall failures.

Quick Fix Guide

Quick Fix Guide

Reason for the Problem	Quick Solution
1. Windows Firewall service stopped	Start and set Windows Defender Firewall service to Automatic.
2. Dependent services (Base Filtering Engine) stopped	Start Base Filtering Engine (BFE) and Windows Defender Firewall dependency services.
3. Corrupted firewall configuration	Reset firewall to defaults via Windows Security or netsh advfirewall reset.
4. Third‑party antivirus or firewall conflict	Temporarily disable or uninstall third‑party security and test Windows Firewall.
5. Group Policy overrides	Run gpupdate /force or check Local Group Policy Editor to restore settings.
6. Corrupted system files	Run sfc /scannow and DISM /Online /Cleanup‑Image /RestoreHealth.
7. Registry misconfiguration	Restore firewall registry keys or import defaults from a healthy PC/backup.
8. Network profile incorrect (Public/Private)	Change network from Public to Private or adjust firewall rules for the profile.
9. Blocked ports/erroneous rules	Use Windows Defender Firewall with Advanced Security to review/remove bad rules.
10. VPN or network software interference	Disable VPN/adapters or uninstall network tools; test firewall again.
11. Malware tampering	Scan with Windows Defender Offline or a bootable AV rescue disk and remove threats.
12. Problematic Windows update or driver	Roll back recent updates or network drivers; use Device Manager or Update history.
13. Firewall service permissions issues	Repair BFE/Firewall service permissions using script or restore from backup.

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Detailed Fixes for “Windows Firewall doesn’t work in Windows 10”

1. Windows Firewall service stopped

Why this causes the problem

• The Windows Firewall won’t function if the core service is stopped or disabled.

Step‑by‑step fix

1. Press Windows key + R, type services.msc, and press Enter.
2. Find Windows Defender Firewall (or Windows Firewall on older builds).
3. Double‑click the service. If Startup type is not Automatic (Delayed Start) or Automatic, set it to Automatic.
4. Click Start if the service is stopped, then Apply and OK.
5. Reboot if needed and test firewall behavior.

Tip: If the service fails to start, note the error message—this often points to dependencies or permissions problems.

2. Dependent services (Base Filtering Engine) stopped

Why this causes the problem

• The firewall depends on the Base Filtering Engine (BFE) and other services; if BFE is stopped the firewall cannot run.

Step‑by‑step fix

1. Open services.msc.
2. Locate Base Filtering Engine, Remote Procedure Call (RPC), and Windows Defender Firewall.
3. Ensure RPC is Running and set to Automatic.
4. Start Base Filtering Engine and set it to Automatic.
5. Start Windows Defender Firewall.
6. If BFE won’t start, check Event Viewer under Windows Logs → System for BFE errors.

Tip: BFE is sensitive—avoid tampering with its registry keys unless instructed.

3. Corrupted firewall configuration

Why this causes the problem

• Corrupt rules or configuration can prevent the firewall UI or service from applying rules properly.

Step‑by‑step fix

1. Open an elevated Command Prompt: press Windows key, type cmd, right‑click Command Prompt → Run as administrator.
2. Reset firewall to defaults: run netsh advfirewall reset.
3. Alternatively go to Settings → Update & Security → Windows Security → Firewall & network protection → Restore firewalls to default.
4. Recreate needed rules after reset.

Note: Resetting removes custom rules—export them first if you need to preserve them via Windows Defender Firewall with Advanced Security → Action → Export Policy.

4. Third‑party antivirus or firewall conflict

Why this causes the problem

• Many security suites replace or disable the Windows Firewall or install drivers that interfere with it.

Step‑by‑step fix

1. Temporarily disable the third‑party firewall/antivirus from its system tray icon or UI.
2. Check whether Windows Firewall automatically enables itself in Firewall & network protection.
3. If disabling helps, fully uninstall the third‑party product via Settings → Apps and reboot.
4. If you prefer keep the third‑party product, configure it to work with Windows Firewall or contact vendor support.

Tip: Use the vendor’s uninstall tool (often available on their site) to remove residual drivers and services.

5. Group Policy overrides

Why this causes the problem

• In corporate or domain environments, Group Policy can disable or configure the firewall centrally.

Step‑by‑step fix (Local or domain)

1. Open an elevated Command Prompt and run gpresult /h C:\gpresult.html, open the file and inspect firewall-related policies.
2. On local machine: press Windows key + R, type gpedit.msc.
3. Navigate to Computer Configuration → Administrative Templates → Network → Network Connections → Windows Defender Firewall.
4. Set any disabled policies to Not Configured or the desired state.
5. Run gpupdate /force in an elevated CMD to apply changes.
6. Reboot and confirm the firewall status in Windows Security.

Note: On domain‑joined machines the domain GPO will override local settings—contact your IT admin.

6. Corrupted system files

Why this causes the problem

• Damaged Windows system files can break firewall components.

Step‑by‑step fix

1. Open an elevated Command Prompt.
2. Run sfc /scannow and wait for completion.
3. If SFC reports issues it couldn’t fix, run DISM /Online /Cleanup‑Image /RestoreHealth.
4. After DISM completes, re‑run sfc /scannow.
5. Reboot and verify firewall functionality.

Tip: These commands can take some time—do them with a stable internet connection for DISM.

7. Registry misconfiguration

Why this causes the problem

• Incorrect or missing firewall registry keys can prevent the service from starting or applying rules.

Step‑by‑step fix

1. Backup the registry: press Windows key + R, type regedit, then File → Export.
2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BFE and … \SharedAccess (Windows Firewall service keys).
3. If keys are missing or suspicious, restore them from a known good backup or another identical OS build.
4. Alternatively use netsh advfirewall reset to restore many defaults.
5. Reboot after registry changes.

Warning: Editing registry is risky—only modify if comfortable and always back up first.

8. Network profile incorrect (Public/Private)

Why this causes the problem

• Firewall rules differ by network profile; an overly restrictive Public profile can block expected traffic.

Step‑by‑step fix

1. Open Settings → Network & Internet → Status.
2. Click Properties under the connected network.
3. Choose Private for trusted networks (home/office) or Public for untrusted networks.
4. Alternatively open Windows Defender Firewall and create rules for both Public and Private profiles if needed.

Tip: Make sure location-aware apps and features are set correctly when switching profiles.

9. Blocked ports/erroneous rules

Why this causes the problem

• A misconfigured rule that blocks essential ports or services appears as “firewall not working” for specific apps.

Step‑by‑step fix

1. Open Windows Defender Firewall with Advanced Security (search in Start).
2. Review Inbound Rules and Outbound Rules for duplicates or blocked entries.
3. Right‑click suspicious rules and choose Disable Rule or Delete.
4. To create an allow rule: Action → New Rule → Program/Port/Predefined and configure carefully.

Tip: Use Windows Firewall → Allowed apps to quickly allow an app through the firewall by name.

10. VPN or network software interference

Why this causes the problem

• VPN clients and virtual adapters can add routes and rules that bypass or confuse firewall behavior.

Step‑by‑step fix

1. Disconnect VPNs and disable virtual adapters: Settings → Network & Internet → Change adapter options.
2. Disable the adapter by right‑clicking and choosing Disable.
3. Test firewall behavior. If resolved, update or reinstall the VPN client and check its integration options.
4. For persistent issues, uninstall VPN, reboot, and reconfigure.

Note: Some enterprise VPNs are configured to manage firewall rules—check vendor docs.

11. Malware tampering

Why this causes the problem

• Some malware disables or corrupts firewall components to avoid detection.

Step‑by‑step fix

1. Update Windows Defender signatures: Windows Security → Virus & threat protection → Check for updates.
2. Run a full scan; if infection suspected, create and run a Windows Defender Offline scan.
3. For stubborn malware, use a reputable bootable antivirus rescue disk (Kaspersky, Bitdefender, etc.), scan from outside Windows and remove threats.
4. After cleaning, run the service and config checks above.

Tip: If malware removed services or drivers, you may need System Restore or a repair install.

12. Problematic Windows update or driver

Why this causes the problem

• Some updates or network driver changes can break firewall behavior.

Step‑by‑step fix

1. Review recent updates: Settings → Update & Security → Windows Update → View update history.
2. Uninstall a recent update temporarily: Uninstall updates (Control Panel route).
3. Open Device Manager (devmgmt.msc) → expand Network adapters, right‑click the adapter → Properties → Driver → Roll Back Driver if available.
4. Reboot and test the firewall.

Tip: If a known update is problematic, Microsoft may have a hotfix—search support articles.

13. Firewall service permissions issues

Why this causes the problem

• Incorrect permissions for BFE or firewall service registry keys prevent services from starting.

Step‑by‑step fix

1. Check Event Viewer for permission denied errors under Windows Logs → System.
2. Use a trusted repair script (search for official Microsoft or well‑known forum scripts) to restore BFE permissions; alternatively restore from system backup.
3. If comfortable, export permissions from a healthy machine’s BFE key using regedit and import here.
4. After changes, reboot and ensure services start.

Warning: Avoid arbitrary permission changes; if unsure, contact a technician.

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Additional tools and prevention

• Create a System Restore point before major firewall or registry edits: Control Panel → System → System Protection → Create.
• Keep Windows and drivers updated but review update history after installs if issues appear.
• Use built‑in logging: enable firewall logging in Windows Defender Firewall with Advanced Security → Properties → Logging to collect dropped/allowed connection details.
• Export firewall rules after configuring them: Action → Export Policy for easy recovery.

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FAQ

How do I permanently disable Windows Firewall?

You can turn it off in Windows Security → Firewall & network protection per network profile, but this is not recommended; use a trusted third‑party firewall instead if needed.

Can I run a third‑party firewall and Windows Firewall at the same time?

Typically no—many third‑party firewalls disable Windows Firewall to avoid conflicts. Choose one product or configure them explicitly to cooperate (rarely recommended).

How can I see which application was blocked by the firewall?

Enable firewall logging (Windows Defender Firewall with Advanced Security → Properties → Logging), then review the log file (default: %systemroot%\system32\LogFiles\Firewall\pfirewall.log) to identify blocked connections.

What if Windows Firewall still won’t start after these steps?

If all fixes fail, consider performing an in‑place repair (Windows 10 repair install) or restore from a full system backup. Contact Microsoft Support or a professional if symptoms persist.

How to prevent firewall issues in the future?

Keep system and security software updated, avoid untrusted security utilities, create configuration backups (export firewall policy), and make regular restore points.

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Conclusion

Most cases where Windows Firewall doesn’t work in Windows 10 are caused by stopped services, conflicts with third‑party security, corrupted configs, or damaged system files; following the checks and step‑by‑step fixes above resolves the problem in nearly every scenario. If you’ve tried everything and the firewall still fails, use a repair install or consult a technician to avoid leaving your PC unprotected.