A:AnswerI put a 16GB stick in mine and it works fine. The board has 4GB hard-wired, so you can only remove one 4GB stick: I did that and ended up with 20GB.
A:AnswerNo, Windows 10 in S mode is a version of Windows 10 that's streamlined for security and performance, while providing a familiar Windows experience. To increase security, it allows only apps from the Microsoft Store, and requires Microsoft Edge for safe browsing.