# Windows Defender Firewall

Windows Service: Microsoft Corporation

Also called mpssvc, windows firewall, windows defender firewall, mpsdrv

Windows, Microsoft

The Windows Filtering Platform service that enforces Windows Defender Firewall rules. It is not the Defender file scanner.

## What you need to know

This is the firewall service. MsMpEng.exe is the antivirus engine.

mpssvc enforces Windows Defender Firewall through Windows Filtering Platform. Turning it off without another firewall opens the PC. It does not scan documents.

- **Important?**: Yes, unless another firewall owns the PC

  **Same as MsMpEng?**: No. That is the AV engine

  **Safe to disable?**: Only if another firewall is active

Feex says

If a game wants the firewall off, I would add a rule. I would not set mpssvc to Disabled and call that a performance tweak.

## What does this service do?

Display name: Windows Defender Firewall. Service name: mpssvc.

It loads firewall profiles, applies rules, and talks to the WFP engine. Third-party firewalls should register as the owner instead of running beside a disabled mpssvc without a plan.

## History on Windows

Still present

Internet Connection Firewall appeared in Windows XP. Windows Vista introduced Windows Filtering Platform and the Windows Firewall service that became Windows Defender Firewall. The service name mpssvc (and the older MpsSvc spelling in some UIs) is the current contract on Windows 10 and Windows 11.

| Earlier form         | Internet Connection Firewall on Windows XP             |
| -------------------- | ------------------------------------------------------ |
| WFP firewall service | Windows Vista (2007)                                   |
| Current name         | Windows Defender Firewall on Windows 10 and Windows 11 |
| Discontinued         | No                                                     |

## Why does Windows need it?

Inbound filtering is the default on client Windows. Without mpssvc, only a third-party filter or a disconnected NIC is left.

## When does it run?

It should run whenever the PC is on a network. Profile changes happen when you switch public and private.

## Should it always be running?

Automatic is the default. Disabled is a hole unless another product owns WFP.

## Can I disable it?

Only if another firewall owns WFP

Disabling mpssvc without a replacement turns off Windows Defender Firewall. Add an app rule for a game instead. If another suite owns the firewall, let that product disable this service.

## What happens if I disable it?

Windows Defender Firewall shows as off. Inbound rules stop. A third-party product may take the slot.

## Process host

mpssvc commonly runs inside svchost.exe. Ending that host can drop other security services in the group. See svchost.exe.

## Dependencies

| Depends on | Windows Filtering Platform and RPC     |
| ---------- | -------------------------------------- |
| Used by    | Windows Security network firewall page |

## Resource behavior

- **CPU**: Low except while compiling a huge rule set

  **Memory**: Small

  **Network**: This is a filter, not a download client

  **Disk**: Low

## Common problems

### Game cannot host a listen port

Add an inbound rule for that exe. Do not disable the service for one title.

### Two firewalls

Windows plus a suite can fight. Pick an owner in Windows Security.

## Troubleshooting

Safe steps first.

### wf.msc or Windows Security firewall page

See which profile is active. The service name is mpssvc.

### Do not "open all ports" as a first step

That is the same as off, with extra lying.

## Technical details

Technical details

| Display name | Windows Defender Firewall |
| ------------ | ------------------------- |
| Service name | mpssvc                    |

## Related

These entities connect to this article. Type is shown on every link.

[Windows Defender: Windows Service](https://feex.it/wiki/service/windows-defender)[MsMpEng.exe: Windows Process](https://feex.it/wiki/process/msmpeng.exe)[Windows Security: Application](https://feex.it/wiki/software/windows-security)

## Sources and verification

Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. [How we research](https://feex.it/wiki/research).

- [Microsoft Learn: Windows Firewall ](https://learn.microsoft.com/windows/security/operating-system-security/network-security/windows-firewall/)· Firewall service
- [Microsoft Learn: WFP ](https://learn.microsoft.com/windows/win32/fwp/windows-filtering-platform-start-page)· Filtering platform
- [Foxhole process map ](https://foxhole.feex.it/)· First-party samples on Windows PCs. Not a lab benchmark.

## Was this article useful?

A yes or no is enough. Pick a reason if you want, or add a short note.

Quick facts

The short identity of this page. Specs, sources, and the full story stay in the article.

- **Display name**: Windows Defender Firewall

  **Service name**: mpssvc

  **Host process**: [svchost.exe](https://feex.it/wiki/process/svchost.exe)

  **Safe to disable?**: You lose the in-box firewall

  **Mapped by Feex**: Seen on Windows PCs in Foxhole

Feex Reviewed: Last verified August 2026

---

Source: [Canonical Feex Wiki page](https://feex.it/wiki/service/windows-firewall/)

[Developer guide](https://feex.it/wiki/developers/) | [API policy](https://feex.it/developers/api-policy/) | [Agent guidance](https://feex.it/wiki/llms.txt)