win7下安装python失败问题

在学习《统计思维 程序员数学之概率统计》时需用python编程，在安装python各种版本总是出现A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor。通过查看事件查看器 Windows日志发现错误提示Error 1722. There is a problem with this Windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor. Action UpdatePip, location: C:\Python34\python.exe, command: -m ensurepip -U --default-pip 。 最终通过百度发现时PYTHONHOME环境变量设置问题。原因是以前安装程序已经设置环境变量PYTHONHOME = C:\OSGeo4W\apps\Python27，将PYTHONHOME设置为python安装路径后问题解决，花了整个大半天时间终于把问题解决。