Не инициализируется npm. Что делать?

Пытаюсь установить node.js. Хочу проинициализироваться npm через npm init - ответил на вопросы, а потом ошибка:
npm ERR! code EPERM
npm ERR! syscall open
npm ERR! path C:\Windows\package.json
npm ERR! errno -4048
npm ERR! Error: EPERM: operation not permitted, open 'C:\Windows\package.json'
npm ERR! [Error: EPERM: operation not permitted, open 'C:\Windows\package.json'] {
npm ERR! errno: -4048,
npm ERR! code: 'EPERM',
npm ERR! syscall: 'open',
npm ERR! path: 'C:\\Windows\\package.json'
npm ERR! }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It's possible that the file was already in use (by a text editor or antivirus),
npm ERR! or that you lack permissions to access it.
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator.

npm ERR! A complete log of this run can be found in: