Windows Defender Firewall
Also called mpssvc, windows firewall, windows defender firewall, mpsdrv
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
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 |
Sources and verification
Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. How we research.
- Microsoft Learn: Windows Firewall · Firewall service
- Microsoft Learn: WFP · Filtering platform
- Foxhole process map · First-party samples on Windows PCs. Not a lab benchmark.
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