Desktop Grids and Service Grids are widely used by scientific communities to execute high throughput application. The European EDGeS project aims at developing the technologies to bridge these two kinds of Grid technologies together. In this paper, we present the development and the application of these new technology to extend the EGEE Grid with XtremWeb- HEP based Desktop Grids. We present the setup of the distributed infrastructure which enables EGEE users' jobs to run on one of the three various XtremWeb-HEP DGs. We describe the new volunteer computing project EGEE@Home based on XtremWeb- HEP middleware. To evaluate the capacity of our technology, we present a performance measurement of the main components and conclude that the overhead is kept reasonable despite the fact that the infrastructure is highly distributed.