在新版nodejs已经集成了npm，所以npm也都安装好了。可以通过输入下面命令来测试是否成功安装

node -v

npm -v

如果安装成功，都会出现版本号
用npm -v测试，报错：

node:internal/modules/cjs/loader:936
  throw err;
  ^

Error: Cannot find module 'D:\lcb\software\nodejs\node_modules\npm\bin\npm-cli.js'
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:17:47 {
  code: 'MODULE_NOT_FOUND',
  requireStack: []
}
node:internal/modules/cjs/loader:936
  throw err;
  ^

Error: Cannot find module 'D:\lcb\software\nodejs\node_modules\npm\bin\npm-cli.js'
[90m    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)[39m
[90m    at Function.Module._load (node:internal/modules/cjs/loader:778:27)[39m
[90m    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)[39m
[90m    at node:internal/main/run_main_module:17:47[39m {
  code: [32m'MODULE_NOT_FOUND'[39m,
  requireStack: []
}

解决办法：

1.卸载重装

2.以管理员方式运行

配好npm之后，在项目中报错，

输入安装依赖命令

npm install

报错如下：

npm ERR! code EPERM
npm ERR! syscall open
npm ERR! path C:\Program Files\nodejs\node_cache\_cacache\tmp\cc62b2b3
npm ERR! errno EPERM
npm ERR! FetchError: Invalid response body while trying to fetch https://registry.npmjs.org/@riophae%2fvue-treeselect: EPERM: operation not permitted, open 'C:\Program Files\nodejs\node_ca
che\_cacache\tmp\cc62b2b3'
npm ERR!     at C:\Program Files\nodejs\node_modules\npm\node_modules\minipass-fetch\lib\body.js:162:15
npm ERR!     at async Arborist.[nodeFromEdge] (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:1061:19)
npm ERR!     at async Arborist.[buildDepStep] (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:930:11)
npm ERR!     at async Arborist.buildIdealTree (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:216:7)
npm ERR!     at async Promise.all (index 1)
npm ERR!     at async Arborist.reify (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\reify.js:149:5)
npm ERR!     at async Install.install (C:\Program Files\nodejs\node_modules\npm\lib\install.js:170:5)
npm ERR!  FetchError: Invalid response body while trying to fetch https://registry.npmjs.org/@riophae%2fvue-treeselect: EPERM: operation not permitted, open 'C:\Program Files\nodejs\node_c
ache\_cacache\tmp\cc62b2b3'
npm ERR!     at C:\Program Files\nodejs\node_modules\npm\node_modules\minipass-fetch\lib\body.js:162:15
npm ERR!     at async Arborist.[nodeFromEdge] (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:1061:19)
npm ERR!     at async Arborist.[buildDepStep] (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:930:11)
npm ERR!     at async Arborist.buildIdealTree (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\build-ideal-tree.js:216:7)
npm ERR!     at async Promise.all (index 1)
npm ERR!     at async Arborist.reify (C:\Program Files\nodejs\node_modules\npm\node_modules\@npmcli\arborist\lib\arborist\reify.js:149:5)
npm ERR!     at async Install.install (C:\Program Files\nodejs\node_modules\npm\lib\install.js:170:5) {
npm ERR!   code: 'EPERM',
npm ERR!   errno: 'EPERM',
npm ERR!   syscall: 'open',
npm ERR!   path: 'C:\\Program Files\\nodejs\\node_cache\\_cacache\\tmp\\cc62b2b3',
npm ERR!   type: 'system',
npm ERR!   requiredBy: '.'
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.

解决办法：

删除npmrc文件，需要注意的是：不是nodejs安装目录npm模块下的那个npmrc文件，而是在C:\Users{账户}\下的.npmrc文件.

继续安装依赖：

npm install

出现下面结果：

npm WARN ERESOLVE overriding peer dependency
npm WARN deprecated [email protected]: The querystring API is considered Legacy. new code should use the URLSearchParams API instead.
npm WARN deprecated [email protected]: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated [email protected]: https://github.com/lydell/resolve-url#deprecated
npm WARN deprecated [email protected]: This project has been renamed to @pawelgalazka/cli-args. Install using @pawelgalazka/cli-args instead
npm WARN deprecated [email protected]: Please upgrade  to version 7 or higher.  Older versions may use Math.random() in certain circumstances, which is known to be problematic.  See https://v8.de
v/blog/math-random for details.
npm WARN deprecated [email protected]: this library is no longer supported
npm WARN deprecated [email protected]: This project has been renamed to @pawelgalazka/cli . Install using @pawelgalazka/cli instead
npm WARN deprecated [email protected]: This SVGO version is no longer supported. Upgrade to v2.x.x.
npm WARN deprecated @hapi/[email protected]: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/[email protected]: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/[email protected]: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/[email protected]: Moved to 'npm install @sideway/address'
npm WARN deprecated @hapi/[email protected]: Switch to 'npm install joi'
npm WARN deprecated [email protected]: request has been deprecated, see https://github.com/request/request/issues/3142
npm WARN deprecated [email protected]: This project has been renamed to 'tasksfile'. Install using 'npm install tasksfile' instead.
npm WARN deprecated [email protected]: Support has ended for 9.x series. Upgrade to @latest
npm WARN deprecated [email protected]: babel-eslint is now @babel/eslint-parser. This package will no longer receive updates.
npm WARN deprecated [email protected]: Chokidar 2 will break on node v14+. Upgrade to chokidar 3 with 15x less dependencies.
npm WARN deprecated [email protected]: core-js@<3.4 is no longer maintained and not recommended for usage due to the number of issues. Because of the V8 engine whims, feature detection in old
 core-js versions could cause a slowdown up to 100x even if nothing is polyfilled. Please, upgrade your dependencies to the actual version of core-js.
npm WARN deprecated [email protected]: Chokidar 2 will break on node v14+. Upgrade to chokidar 3 with 15x less dependencies.
npm WARN deprecated [email protected]: 3.x is no longer supported
npm WARN deprecated [email protected]: This loader has been deprecated. Please use eslint-webpack-plugin
npm WARN deprecated [email protected]: 3.x is no longer supported

added 1568 packages, and audited 1569 packages in 3m

105 packages are looking for funding
  run `npm fund` for details

37 vulnerabilities (23 moderate, 11 high, 3 critical)

To address issues that do not require attention, run:
  npm audit fix

To address all issues possible (including breaking changes), run:
  npm audit fix --force

Some issues need review, and may require choosing
a different dependency.

Run `npm audit` for details.
npm notice
npm notice New minor version of npm available! 8.1.2 -> 8.3.0
npm notice Changelog: https://github.com/npm/cli/releases/tag/v8.3.0
npm notice Run npm install -g [email protected] to update!
npm notice

原因：默认的安装源是国外网站，国内访问不了无法获取依赖包信息。

解决办法：添加

npm config set registry http://registry.npm.taobao.org/

其他常见命令：

# 查看自己的安装源
npm config get registry

# 更换npm源为国内淘宝镜像
npm config set registry http://registry.npm.taobao.org/

# 或者更换为国内npm官方镜像
npm config set registry http://registry.cnpmjs.org/

# 还原npm源
npm config set registry https://registry.npmjs.org/

继续执行：

npm install

结果如下：

up to date in 2s

105 packages are looking for funding
  run `npm fund` for details

即安装完成。

npm启动项目命令

npm run dev