Aug 23

Even when told not to, Windows 10 just can’t stop talking to Microsoft (Ars Technica, Aug 13, 2015):

It’s no wonder that privacy activists are up in arms.

Windows 10 uses the Internet a lot to support many of its features. The operating system also sports numerous knobs to twiddle that are supposed to disable most of these features and the potentially privacy-compromising connections that go with them.

Unfortunately for privacy advocates, these controls don’t appear to be sufficient to completely prevent the operating system from going online and communicating with Microsoft’s servers.

For example, even with Cortana and searching the Web from the Start menu disabled, opening Start and typing will send a request to to request a file called threshold.appcache which appears to contain some Cortana information, even though Cortana is disabled. The request for this file appears to contain a random machine ID that persists across reboots.

Some of the traffic is obviously harmless. On connecting to a new network, Windows machines try to request two URLs ( and, the former over IPv4, the latter over IPv6) to ascertain whether a given network is routed to the Internet and if there is a captive portal in the way (NCSI stands for “Network Connection Status Indicator”). These requests are very bare, with no machine IDs or other data sent. If you want to turn even these off there is a way to do so, but the privacy impact is minimal.

Some of the traffic looks harmless but feels like it shouldn’t be happening. For example, even with no Live tiles pinned to Start (and hence no obvious need to poll for new tile data), Windows 10 seems to download new tile info from MSN’s network from time to time, using unencrypted HTTP to do so. While again the requests contain no identifying information, it’s not clear why they’re occurring at all, given that they have no corresponding tile.

Other traffic looks a little more troublesome. Windows 10 will periodically send data to a Microsoft server named This server seems to be used for OneDrive and some other Microsoft services. Windows 10 seems to transmit information to the server even when OneDrive is disabled and logins are using a local account that isn’t connected to a Microsoft Account. The exact nature of the information being sent isn’t clear—it appears to be referencing telemetry settings—and again, it’s not clear why any data is being sent at all. We disabled telemetry on our test machine using group policies.

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