This fix is specific to windows, you could edit your preferences like jorum. OR you can add it to your windows "Path" which may be more helpful in the future.
Start > Control Panel > System > Advanced System Settings > Environment Variables...
Select your PATH and click edit.
ADD this to the end of the Variable Value:
;C:\Users\YOURUSERNAMEHERE\node_modules\jshint\bin
TO TEST: Open a command prompt and type
jshint -v
and you should get a version number and not an error.
What you just did was added told your OS where it can find jshint, your install location may be different, in that case just search for a jshint folder on your system that has a /bin folder inside it and link there instead. NOTE the semi-colon(;) at the beginning separates different PATH's so be sure its included.