The technology, which Microsoft calls "Windows Update Delivery Optimization" (WUDO), is turned on by default for all editions of Windows 10. But only some versions -- notably Windows 10 Home and Windows 10 Pro -- are set up to deliver updates and apps to other devices when connected to the Internet.
The versions used mainly in the enterprise -- Windows 10 Enterprise and Windows 10 Education -- only share updates and apps within a local network.
Here's the low-down on the update techniology:
Some users were annoyed: "P2P [peer-to-peer] isn't bad. But it should not be turned on by default!" wrote someone identified as RMJ1984 on Reddit. "It's totally unacceptable just using peoples' bandwidth."
Microsoft has not yet made public any technical documentation about WUDO, but the service can be turned off or restricted. To do so, go to "Settings," click the "Update & security" icon, then the "Advanced options" link under "Windows Update." In the next window, select "Choose how updates are delivered" and turn off WUDO by moving the slider to Off. To simply restrict sending locally cached updates and apps to devices on the same local network, choose "PCs on my local network" near the bottom.
With reports by Gregg Keizer at Computerworld.