Microsoft's privacy policy for Windows 10 Technical Preview states the company may collect information about your device, voice input, information on files and text you enter when you participate in the pre-release program of the next version of Windows.
In its privacy policy covering the Windows Technical Preview, Microsoft specifically states what is collected. Collected data includes the name, email address of the user working with Windows 10. But also preferences and interests, browsing, search and file history, phone call and SMS data, device configuration and sensor data and application usage".
In another paragraph the company states it may collect information the device and applications and use it for purposes such as determining or improving compatibility. Also voice input is collected, Microsoft states about that they can, "use voice input features, such as speech-to-text" and also explain why it does so, "we may collect voice information and use it for purposes such as improving speech processing".
When a file is opened on Windows 10 Technical Preview, also information about the file, the application used to open the file and how long it takes is collected. According to Microsoft it is used for purposes such as improving performance. And last but not least, the company states it may collect typed characters (text input) and use them for purposes such as improving auto-complete and spell check features.
Although this list is pretty extensive, Microsoft lists all of these as examples. In reality the company might collect more and other data and use it for different purposes than the stated examples.
Thanks for the tip Ch3vr0n!
