In pervasive computing environments, users can interact with a wide range of services, but which do not include legacy application services such as interactive desktop applications. How to use legacy service as a kind of transparent service mechanism in a pervasive computing environment is an important problem to solve during the transition from personal computing to pervasive computing. This paper presents a user-centric service framework that coordinates application services over network and heterogeneous networked devices nearby users to form a user's virtual computing environment. It also provides legacy support without modification to existing softwares based on virtual desktop and virtual device