Node 8.0 install, but npm stuck on old version

Installed node version v8 on windows 10. It says it comes delivered with npm 5.... But it's stuck on 3.5.3

λ npm i -g npm
npm ERR! Windows_NT 10.0.14393

npm ERR! argv "npm" "i" "-g" "npm"

npm ERR! node v8.0.0

**npm ERR! npm  v3.5.3**

**npm ERR! code MODULE_NOT_FOUND**

**npm ERR! Cannot find module 'internal/fs'**
npm ERR!

npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>


npm ERR! Please include the following file with any support request:
npm ERR!     C:\Users\user\npm-debug.log

What i've done:

• Uninstall node and reinstall it
• Install a different version of node (7.7.0) and see if it updated npm
• used npm clean cache -f

And none of these things worked... So any ideas?