the term 'node' 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.
chances are that you might have altered your system path settings,
the best advice l can give is to uninstall and install your node.
download latest version from : https://nodejs.org/en/
Hope it solves your problem.