Windows 服务被设计用于需要在后台运行的应用程序以及实现没有用户交互的任务。为了学习这种控制台应用程序的基础知识，C（不是C++）是最佳选择。本文将建立并实现一个简单的服务程序，其功能是查询系统中可用物理内存数量，然后将结果写入一个文本文件。最后，你可以用所学知识编写自己的 Windows 服务。-Windows service is commonly used by program which running without intactive with users. To learn how to develop it, C is the best choice. This article will give you an example about how to develop a basic service program which can query the physical memory and write the results to a text file. You can develop your own service program after this pratice.