如果使用sbt方法构建，则还需要git

在计算机上安装Scala，sbt和git。下载Spark源代码并运行以下命令

If you are using building with sbt approach, then you'll need git also.
Install Scala, sbt and git on your machine. Download Spark source code and run following command

sbt assembly

如果使用预构建版本，请按以下步骤操作：

如何在Windows7上以独立模式运行Apache Spark

In case,if you use prebuilt release,Here is the step by step process:
How to run Apache Spark on Windows7 in standalone mode