One of the most obvious user interface changes is the fact that almost all app windows and many user interface controls will get a rounded corner effect applied to them or windows 11 border radius.The question came up during the RAD Studio 11 launch Q & A whether the Embarcadero team had an example of using that API. Jim McKeeth pasted a short example of how to do it in the question window but it was a little hard to read and only a partial example so I've taken that answer and built a more complete demo for you to download and play with. I've created a universal unit with a simple call in there - all you need to do is pass it a Window handle and Windows 11 will do your bidding.