From: http://www.journalofaccountancy.com/issues/2017/jul/prevent-windows-10-from-spying-on-you.html
Q. Is it true that Windows 10 records my every keystroke?
A. Depending on how Windows 10 was configured during setup, yes. Windows 10 can not only record your every keystroke, but it can also record your voice as you talk (assuming your computer is equipped with a microphone that’s turned on) and even your handwriting if you use a stylus to enter handwritten data. Microsoft embedded these types of recording activities in the Beta versions of Windows 10. As a result, examining the data collected reportedly enabled Microsoft developers to see what users were doing and working on when software glitches occurred, which aided developers in locating and correcting programming issues. Microsoft found the tool so useful that the company kept the recording feature in the final release of Windows 10.
You can check to see if Microsoft is tracking your computing activity and disable this feature as follows. From the Windows 10 Start menu, select Settings (the settings cog icon), Privacy, Speech, inking, & typing. If the option reads Get to know me, then this recording feature is already disabled on your computer. If the option reads Stop getting to know me, as pointed out in the screenshot below, then click this option to disable the recording functionality.
Disabling this functionality will clear any keystroke, voice, and handwriting data files that have been recorded on your computer and will prevent future recording activities.
