Desktop Grid has recently been an attractive computing paradigm for high throughput applications. A desktop Grid can be defined as a peer-to-peer computing environment based on desktop machines. However, desktop Grid computing is complicated by heterogeneous capabilities, failures, volatility, and lack of trust because it is based on Internet connected desktop computers. Decentralization, Interoperability, scheduling, Connectivity and Fault tolerance are important issues of desktop Grid. In this work we present HIMAN, a pure P2P Desktop Grid framework. HIMAN accomplishes the following: full decentralization, resolving Interoperability and connectivity problems by implementing standard communication protocols together with a pull mode interaction model, efficient fault-tolerance based on incremental checkpointing, and decentralized scheduling based on fuzzy logic. Experimental results show that the implemented techniques improved the fault tolerance, beside achieving full decentralization, Interoperability and solving connectivity problems. Implementing the proposed distributed scheduling mechanism maximized the resource utilization of the executing workers.