netio.sys

Windows Network I/O System Driver

Kernel DriverStableNetworking

CPU Usage

1-5%

Memory

0.5-3 MB

Location

C:\Windows\System32\drivers

Publisher

Microsoft Corporation

Quick Answer

netio.sys is a legitimate Windows kernel driver. It handles core network I/O between applications and the Windows networking stack, running in the background to support sockets, VPNs, and firewall interactions.

Is it a Virus?

✔ NO - Safe

Must be located at C:\Windows\System32\drivers\netio.sys

Warning

Kernel drivers can spike with legitimate activity

netio.sys is expected to run continuously; unusual CPU spikes or malicious tampering should prompt verification

Can I Disable?

✔ YES

Disabling netio.sys is not recommended as it will disrupt normal networking

What is netio.sys?

netio.sys is a Windows kernel-mode driver responsible for managing core network I/O operations between user-space applications and the Windows networking stack. It coordinates socket handling, data buffering, and packet delivery, working with NICs, VPN clients, and firewalls. It runs continuously in the background as a foundational OS component.

Operates in kernel space to queue and dispatch network packets, interfacing with NDIS and NIC hardware. It uses memory buffers and interrupts to support stable, low-latency data transfer for apps, services, and adapters, including VPNs and virtual networks.

Quick Fact: netio.sys is part of the Windows networking stack and is loaded at boot; it coordinates kernel-level I/O between software and hardware.

Types of Network I/O Processes

Network I/O Driver: Kernel-space component handling packet routing and buffering
VPN/NAT Modules: Kernel extensions that tunnel or translate packets through VPNs
Firewall Hooks: Kernel hooks that enforce policy for inbound/outbound traffic
NDIS Interfaces: Network Driver Interface Specification bridging drivers and NICs

Is netio.sys Safe?

Yes, netio.sys is safe when it is the legitimate Windows kernel driver located in the standard path and digitally signed by Microsoft.

Is netio.sys a Virus or Malware?

The real netio.sys is not a virus. Malware may mimic file names, so verify location and signature.

How to Tell if netio.sys is Legitimate or Malware

File Location: Must be in C:\Windows\System32\drivers\netio.sys. Any netio.sys elsewhere is suspicious.
Digital Signature: Right-click the file in File Explorer → Properties → Digital Signatures. Should show a Microsoft signature (e.g., Microsoft Corporation).
File Integrity: Check via System File Checker: open Command Prompt as admin and run sfc /scannow to validate system files.
Resource Usage: Normal operation uses minimal CPU/memory. Unusually high usage or random spikes warrants malware check.

Red Flags: If netio.sys is not in C:\Windows\System32\drivers, lacks a valid signature, or shows persistent abnormal resource use, scan with updated antivirus and consider a repair install.

Why Is netio.sys Running on My PC?

netio.sys runs as part of Windows networking to provide low-level I/O support. It can appear even when you are not actively using a network-intensive app because it services background networking tasks.

Reasons it's running:

Active Network Activity: Your system is handling open sockets, streaming, or background network tasks; netio.sys manages packet buffering and delivery.
VPN or Virtual Network Adapters: VPN clients and virtual NICs load kernel components that route traffic through netio.sys.
Firewall and Security Software: Security tools install kernel drivers that intercept and inspect traffic via the Windows networking stack.
Background Windows Services: Services like Windows Update or Defender network telemetry rely on kernel I/O to fetch updates and signals.
Network Adapter Power Management: Power-saving features and wake-on-network events trigger netio.sys activity to maintain connectivity readiness.

Can I Disable or Remove netio.sys?

Disabling netio.sys is not recommended. It is a core Windows kernel driver essential for networking; removing or disabling it can break connectivity and stabilize the OS.

How to Stop netio.sys Interference (Safe Measures)

Identify and reduce load: Close nonessential VPN clients or virtualization tools temporarily and monitor impact
Update components: Run Windows Update and update network drivers to ensure compatibility
Run network troubleshooter: Settings > Update & Security > Troubleshooter > Network Adapter
Perform a network reset if problems persist: Settings > Network & Internet > Status > Network reset

How to Repair Networking Without Uninstalling

✔ Open Settings > Update & Security > Recovery > Reset this PC (keep files) to fix networking if needed
✔ Run System File Checker: Admin Command Prompt > sfc /scannow
✔ Run DISM: Admin Command Prompt > DISM /Online /Cleanup-Image /RestoreHealth

Common Problems: High Network Latency or Resource Use

If netio.sys appears to impact performance, investigate typical drivers, VPNs, and NIC health that can influence kernel I/O.

Common Causes & Solutions

VPN or VPN-like kernel modules: Update VPN client; disable it temporarily to test; ensure kernel components are trusted
Outdated NIC drivers: Update network adapter drivers from the vendor or Windows Update
Background network tasks: Limit background tasks or stagger updates; use Windows task scheduler to control timing
Malware masquerading as netio.sys: Run full system antivirus/malware scan and verify digital signatures
Firewall misconfigurations: Reset firewall rules to default and re-allow legitimate traffic
System file corruption: Run SFC and DISM to restore integrity

Quick Fixes:
1. Open Task Manager and inspect network-related processes
2. Update NIC and VPN drivers
3. Run Windows Update and apply security patches
4. Run Windows network troubleshooter
5. Perform a network reset if issues persist

Frequently Asked Questions

Is netio.sys a virus?

No, the legitimate netio.sys from Microsoft is a kernel driver required for networking. Verify its location at C:\Windows\System32\drivers\netio.sys and its digital signature.

Why is netio.sys using CPU?

Temporary CPU usage can occur during active network I/O, VPN activity, or heavy background networking tasks. If usage stays high, scan for malware and review network adapters.

Can I delete netio.sys?

No. netio.sys is a core Windows component. Deleting it will break networking. If problems persist, use system repair options rather than removal.

Where is netio.sys located?

The legitimate file is located at C:\Windows\System32\drivers\netio.sys. Any other location is suspicious and should be scanned for malware.

How can I reduce netio.sys impact on performance?

Update networking drivers, disable unnecessary VPNs or virtualization tools, run malware scans, and perform a network reset if required.

How do I verify netio.sys is legitimate?

Check file path, verify digital signatures, run SFC/DISM, and review system integrity to ensure the file matches Microsoft’s signature.