While it's known for some time now that Windows 10 sends a lot of data to Microsoft servers, it appears that even when you tell the operating system not to, it just can't stop talking to Microsoft. ARS Technica writes today that while Windows 10 has numerous settings that are supposed to disable most of these features, it seems they are still insufficient to prevent the OS from sending data to Microsoft:
For example, even with Cortana and searching the Web from the Start menu disabled, opening Start and typing will send a request to www.bing.com 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.
Other traffic looks a little more troublesome. Windows 10 will periodically send data to a Microsoft server named ssw.live.com. 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 log-ins 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 telemtry on our test machine using group policies.