Turn off peer-to-peer update sharing (Delivery Optimization) — via Microsoft Learn

The easy way

1. The easy way: Settings → Windows Update → Advanced options → Delivery Optimization → turn off Allow downloads from other devices.
2. Check what it's done: the Activity monitor on the same page shows downloads by source and upload totals this month.
3. By policy (Pro and up): Computer Configuration > Administrative Templates > Windows Components > Delivery Optimization > Download Mode = HTTP only (0).

Registry change

Double-click a .reg file and confirm to merge it. Right-click → Edit first if you want to read it, which is always a good idea with any .reg file from the internet.

Apply

Windows Registry Editor Version 5.00

; Oddbyte.Me: Turn off peer-to-peer update sharing (Delivery Optimization)

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization]
"DODownloadMode"=dword:00000000

Undo

Windows Registry Editor Version 5.00

; Oddbyte.Me: undo Turn off peer-to-peer update sharing (Delivery Optimization)

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization]
"DODownloadMode"=-

Same thing from a command prompt

Run in an administrator Command Prompt or Terminal.

reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization" /v "DODownloadMode" /t REG_DWORD /d 0 /f

Undo:

reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization" /v "DODownloadMode" /f

Don't use the old Bypass mode (100) found in many guides: Microsoft deprecated it in Windows 11 and says it can make some downloads fail with error 0x80d03002. Use 0 to switch off peering; Microsoft says 99 (Simple) is only for devices without internet access. Turning off peering doesn't stop updates downloading — it only changes where they come from. The same policy folder has bandwidth caps.