Ionic3 build Error - upgrading from ionic2 to ioni3

Appreciate your patience, but again I am failing with npm install now.

PS D:\app> npm install
Error: Cannot find module 'safe-buffer'
    at Function.Module._resolveFilename (module.js:469:15)
    at Function.Module._load (module.js:417:25)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (C:\Users\Deep\AppData\Roaming\npm\node_modules\npm\node_modules\request\lib\helpers.js:5:36)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
npm ERR! Windows_NT 10.0.15063
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\Deep\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "install"
npm ERR! node v6.11.0
npm ERR! npm  v3.10.10
npm ERR! code MODULE_NOT_FOUND

npm ERR! Cannot find module 'safe-buffer'
npm ERR!
npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>