Distributed Shared Memory (DSM) is one of the main approaches to implement distributed computing. The purpose of this project is to design and implement a prototype DSM that runs on popular TCP/IP networked Window PCs without special compliers and/or linkers. Our DSM uses lock based scope consistency (ScC), and supports central model, multiple server model and fully distributed model. We use object-oriented method to encapsulate these models within one framework. We provide C++ APIs and a DSM engine for C++ programmers to use DSM functions. The project is developed using C++ and Winsock APIs under Windows NT platform.