Regedit Key for Network QoS Markings in Windows

This guide covers the specific Windows Registry keys that manage system-wide Quality of Service (QoS) packet markings. You will learn the exact registry paths for system TCP/IP QoS parameters and Group Policy-driven DSCP (Differentiated Services Code Point) markings, as well as how to configure them to prioritize network traffic across your system.

Primary QoS Registry Keys

In Windows, system-wide network Quality of Service (QoS) markings are controlled primarily through two registry locations depending on whether you are configuring the core TCP/IP stack behavior or policy-based traffic rules.

1. Core TCP/IP QoS Configuration Key

The low-level system configuration for TCP/IP QoS behavior is located at:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\QoS

If the QoS subkey does not exist under Tcpip, it can be created manually.

A critical value under this key is: * Value Name: Do not use NLA * Type: REG_SZ (String Value) * Value Data: 1 (or "1")

By default, Windows policy-based QoS markings are only applied if the network interface is connected to an Active Directory domain via Network Location Awareness (NLA). Setting Do not use NLA to 1 enables QoS markings on all network types, including workgroups, local subnets, and standard public/private networks.

2. Policy-Based QoS Rules Key

When QoS policies are defined either locally or via Active Directory Group Policy to assign DSCP values to specific applications, IP addresses, or ports, the rules are stored at:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\QoS

Each configured policy appears as a subkey under \QoS, containing values for: * DSCP Value (REG_SZ or REG_DWORD): The DSCP priority tag (0–63) applied to packet headers. * Application Name (REG_SZ): The executable name the rule applies to. * Protocol (REG_SZ): The network protocol (e.g., TCP, UDP, or *). * Local Port / Remote Port (REG_SZ): Specified port ranges for the traffic. * Local IP / Remote IP (REG_SZ): Target or source IP constraints.

How to Apply System-Wide QoS Settings

  1. Press Win + R, type regedit, and press Enter to open the Registry Editor.

  2. Navigate to:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip

  3. Right-click Tcpip, select New > Key, and name it QoS.

  4. Right-click the new QoS key, select New > String Value, and name it Do not use NLA.

  5. Double-click Do not use NLA and set its Value data to 1.

  6. Restart the computer to apply the TCP/IP stack changes.