I don't think I'm going to bother upgrading from Windows 7.
This is the body of an e-mail I received last Friday from an IT security company - I have no idea how I ended up on their contact list but I get a "Security Threat of the Week" e-mail every Friday:
If you were paying attention, a couple of weeks back we raised the subject of the enormous amount of data being exfiltrated from your machines to the mountain halls (well DataCentres) of Microsoft when you use Windows 10, especially if it is configured with default express settings.
What data do they collect? Well quite a lot actually:
· Search queries submitted to Bing
· A voice command to Cortana
· Private communications including email content
· Information from a document uploaded to OneDrive
· Requests to Microsoft for support
· Error reports
· Information gathered from cookies
· Data collected from third parties
This was discovered just after the launch of Windows 10, when Microsoft changed their End User License Agreement to make it ok, at least on paper.