Regedit Delivery Optimization P2P Settings

Windows Delivery Optimization uses peer-to-peer (P2P) functionality to share update files between local computers and internet sources, conserving network bandwidth. While this feature can be managed through the Windows Settings app and Group Policy, administrators can also configure or disable peer-to-peer download settings directly through the Windows Registry. This guide details the exact registry key and values required to control Delivery Optimization behavior.

The Delivery Optimization Registry Key

The primary registry key used to control Delivery Optimization policies and P2P download settings is:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization

If you are not using Group Policy and want to configure system-level defaults, the settings are stored under:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\DeliveryOptimization\Config

The DODownloadMode Value

Within the Delivery Optimization key, the specific value that controls P2P downloading is a 32-bit DWORD named DODownloadMode.

The numerical data assigned to DODownloadMode dictates how Windows sends and receives update files:

• 0 (HTTP Only): Disables peer-to-peer functionality. Updates are downloaded exclusively from Microsoft servers via HTTP.
• 1 (LAN / Local Network): Enables P2P sharing only between devices connected to the same local area network (subnet).
• 2 (Group): Enables P2P sharing within an Active Directory site, domain, or custom defined group ID.
• 3 (Internet): Enables P2P sharing across both the local network and internet-connected peers.
• 99 (Simple Mode): Disables cloud checks and peering entirely. Updates download directly from the source without contacting Delivery Optimization cloud services.
• 100 (Bypass Mode): Completely bypasses Delivery Optimization and reverts to the Background Intelligent Transfer Service (BITS).

How to Apply the Settings via Regedit

1. Press Win + R, type regedit, and press Enter to open the Registry Editor.
2. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization
3. If the DeliveryOptimization folder does not exist, right-click the Windows key, select New > Key, and name it DeliveryOptimization.
4. Right-click the DeliveryOptimization key, select New > DWORD (32-bit) Value, and name it DODownloadMode.
5. Double-click DODownloadMode, set the Base to Hexadecimal, and enter the desired value (for example, 0 to disable P2P or 1 for local network only).
6. Click OK and restart the computer or restart the DoSvc (Delivery Optimization) service for changes to take effect.