Microsoft plans big Windows 10 UI refresh in 2021 codenamed ‘Sun Valley'Windows CentralMicrosoft is preparing a major OS update for Windows 10 in 2021 that sources say will bring with it a significant design refresh to the Windows UI. I'm told that Microsoft is planning to update many top-level user interfaces such as the Start menu, Action Center, and even File Explorer, with refreshed modern designs, better animations, and new features.