npm install bower -G 报错

bower@0.7.0 postinstall \node_modules\bower node cleanup

events.js:72 throw er; // Unhandled 'error' event ^ Error: spawn ENOENT at errnoException (child_process.js:980:11) at Process.ChildProcess._handle.onexit (child_process.js:771:34) npm ERR! weird error 8 npm ERR! not ok code 0