Error after upgrade ... but upgrade seems successful about npm-windows-upgrade HOT 4 CLOSED

PS C:\SolutionTemplates\WebSolution> npm-windows-upgrade
npm-windows-upgrade 0.2.3
? This tool will upgrade npm. Do you want to continue? Yes
? Which version do you want to install? 2.12.1
Upgrading.. /Error:  module.js:338
    throw err;
          ^
Error: Cannot find module 'semver'
    at Function.Module._resolveFilename (module.js:336:15)
    at Function.Module._load (module.js:278:25)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (C:\Users\Warren\AppData\Roaming\npm\node_modules\npm\lib\config\defaults.js:7:14)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)

Upgrading.. -

You wanted to install npm 2.12.1, but the installed version is2.11.2.
Please consider reporting your trouble to http://aka.ms/npm-issues.
Here is the output from the upgrader script:
[ 'All done!\r\n' ] [ 'module.js:338\r\n    throw err;\r\n          ^\r\nError: Cannot find module \'semver\'\r\n    at
Function.Module._resolveFilename (module.js:336:15)\r\n    at Function.Module._load (module.js:278:25)\r\n    at Module.
require (module.js:365:17)\r\n    at require (module.js:384:17)\r\n    at Object.<anonymous> (C:\\Users\\Warren\\AppData
\\Roaming\\npm\\node_modules\\npm\\lib\\config\\defaults.js:7:14)\r\n    at Module._compile (module.js:460:26)\r\n    at
 Object.Module._extensions..js (module.js:478:10)\r\n    at Module.load (module.js:355:32)\r\n    at Function.Module._lo
ad (module.js:310:12)\r\n    at Module.require (module.js:365:17)\r\n' ]
PS C:\SolutionTemplates\WebSolution>