This error happens due to a security policy that won't let scripts be executed on your system without you having approved of it. You can do so by opening up a PowerShell window with administrative rights (search for PowerShell in the main menu and select Run as administrator from the context menu) and entering:
set-executionpolicy remotesigned

出现这个报错的原因是，windows出于安全策略的考虑，默认情况下是不允许运行脚本的，因此，当你在进行一些关联命令行脚本的操作之前。需要让windows解除相关限制。
你需要以管理员身份运行命令行，输入
set-executionpolicy remotesigned