npm ERR! Windows_NT 10.0.10586
npm ERR! argv "C:\Software\Program Files\JetBrains\WebStorm 2017.1.4\nodeJs\node.exe" "C:\Software\Program Files\JetBrains\WebStorm 2017.1.4\nodeJs\node_modules\npm\bin\npm-cli.js" "install" "yarn" "-g"
npm ERR! node v6.11.0
npm ERR! npm  v3.10.10
npm ERR! path C:\Software\Program Files\JetBrains\WebStorm 2017.1.4\nodeJs\global\yarn
npm ERR! code EISDIR
npm ERR! errno -4068
npm ERR! syscall open

npm ERR! eisdir EISDIR: illegal operation on a directory, open 'C:\Software\Program Files\JetBrains\WebStorm 2017.1.4\nodeJs\global\yarn'
npm ERR! eisdir This is most likely not a problem with npm itself
npm ERR! eisdir and is related to npm not being able to find a package.json in
npm ERR! eisdir a package you are trying to install.

npm ERR! Please include the following file with any support request:
npm ERR!     C:\Windows\system32\npm-debug.log

The above is the error log when npm installs yarn. I have tried reinstalling nodejs and running cmd with administrative privileges, but none of them succeeded. How to solve it?