ionic2 npm install fails on "angular/forms" not found

[darthwalsh]

Running on Windows from the ionic2 directory npm install fails with the error

npm ERR! 404 Not Found
npm ERR! 404
npm ERR! 404 'angular/forms' is not in the npm registry.
npm ERR! 404 You should bug the author to publish it
npm ERR! 404
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, or http url, or git url.

npm ERR! System Windows_NT 10.0.15063
npm ERR! command "C:\Program Files\nodejs\node.exe" "C:\ProgramData\chocolatey\lib\npm\tools\node_modules\npm\bin\npm-cli.js" "install"
npm ERR! cwd c:\code\temp\react-native-vs-ionic-todos\ionic2
npm ERR! node -v v5.10.0
npm ERR! npm -v 1.4.9
npm ERR! code E404