Desktop Window Manager

The Desktop Composition Engine (or DCE) is a theme rendering engine used in early builds of Windows Longhorn. It is present starting with Windows Longhorn build 3683 but in a buggy state. Starting with build 4008, DCE only provides transparency effects. It synchronized with WinFS, Avalon and other internal Windows databases, as well as providing visual effects. Starting with build 4066, DCE was replaced by Desktop Window Manager