PowerShell cannot be loaded- execution policy

PowerShell脚本无法运行，报错：

cannot be loaded. The file 
xxxx is not digitally signed. You cannot run this script on the current system. For more information about running scripts and setting 
execution policy, see about_Execution_Policies at http:/go.microsoft.com/fwlink/?LinkID=135170.
At line:1 char:1

解决方法：

右键点击该执行文件，unblock->Apply即可