你可以通过双击运行一个jar，你只需要确保Java与.jar文件相关联。最简单的方法是重新安装JRE（通常会为你完成）。

You can run a jar by double clicking it, you just have to make sure that Java is associated with .jar files. The easiest way to do this is by reinstalling the JRE (which generally does it for you).

否则你需要修改一些Windows属性（我是不确定您运行的是哪个版本的Windows）将.jar文件指向javaw.exe的实例。

Otherwise you will need to modify some of your Windows properties (I'm not sure what version of Windows you are running) to point .jar files to the instance of javaw.exe.

这是一个关于如何操作的Windows 7页面的链接。