命令不再与Visual Studio Powershell一起使用

Question

我曾经一直使用这些命令，但是突然我开始出现此错误，并且不再起作用。

git : The term 'git' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ git
+ ~~~
    + CategoryInfo          : ObjectNotFound: (git:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

npm，tsnode等也发生了同样的事情。请帮助我，我不想使用其他编辑器。