This paper proposes a decentralised system for managing Desktop Grid (DG). The idea is to bypass the main drawback of existing systems putting all the control on a single master that can fails. Here, each node can play alternatively the role of client or server. Our main contribution is to design the PastryGrid protocol (based on Pastry) for DG in order to decentralise the execution of a distributed application with precedence between tasks. Comparing to a centralised system, we evaluate our approach over 205 machines executing 2500 tasks. The results show that our decentralised system runs better than the same system configured as a master/slave because it gives less overhead.