Reports suggest that Windows 10 is going to get some significant design changes at some point in 2021. These changes will include updates to parts of the user interface like the start menu, File Explorer, action center and more. 

According to Windows Central, internal documents from Microsoft suggest that this update will be "reinvigorating" and is set to modernise the Windows experience. 

This overhaul is being referred to as "Sun Valley" and is seen as a UI project which will release near the end of 2021. 

Windows 10 released back in 2015 and though it represented a good leap forward in many ways, its overall design has mostly remained the same since then. It makes sense, therefore, for the company to be working on changing the operating system to keep it fresh, modern and relevant. 

Although there's no word on what exactly is set to change at this point, sources have told Windows Central that we can expect to see a re-thought and re-designed Start menu and Action Center with inspiration from Windows 10X.

The changes are being worked on currently and testing will need to happen before a full roll-out, so we're likely to not see any major updates until late in 2021.