Errors while installing node package manager - node.js

Question

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Date: 2017-09-26T04:39:22.671Z
Hash: 916808702f64c1919061
Time: 8652ms
chunk {inline} inline.bundle.js, inline.bundle.js.map (inline) 5.83 kB [entry] [rendered]
chunk {main} main.bundle.js, main.bundle.js.map (main) 1.06 kB {vendor} [initial] [rendered]
chunk {polyfills} polyfills.bundle.js, polyfills.bundle.js.map (polyfills) 323 bytes {inline} [initial] [rendered]
chunk {styles} styles.bundle.js, styles.bundle.js.map (styles) 12.3 kB {inline} [initial] [rendered]
chunk {vendor} vendor.bundle.js, vendor.bundle.js.map (vendor) 338 kB [initial] [rendered]
ERROR in C:/Users/PC/src/app/app.component.ts (1,27): Cannot find module '#angular/core'.
ERROR in C:/Users/PC/src/app/app.component.ts (8,14): Experimental support for decorators is a feature that is subject to change in a future release.
Set the 'experimentalDecorators' option to remove this warning.
ERROR in C:/Users/PC/src/app/app.module.ts (1,31): Cannot find module '#angular/platform-browser'.
ERROR in C:/Users/PC/src/app/app.module.ts (2,26): Cannot find module '#angular/core'.
ERROR in C:/Users/PC/src/app/app.module.ts (16,14): Experimental support for decorators is a feature that is subject to change in a future release. Se
t the 'experimentalDecorators' option to remove this warning.
ERROR in C:/Users/PC/src/main.ts (1,32): Cannot find module '#angular/core'.
ERROR in C:/Users/PC/src/main.ts (2,40): Cannot find module '#angular/platform-browser-dynamic'.
ERROR in Error: Could not resolve module #angular/core
at StaticSymbolResolver.getSymbolByModule (C:\Users\PC\node_modules\#angular\compiler\bundles\compiler.umd.js:25601:30)
at StaticReflector.findDeclaration (C:\Users\PC\node_modules\#angular\compiler\bundles\compiler.umd.js:24350:63)
at StaticReflector.initializeConversionMap (C:\Users\PC\node_modules\#angular\compiler\bundles\compiler.umd.js:24568:36)
at new StaticReflector (C:\Users\PC\node_modules\#angular\compiler\bundles\compiler.umd.js:24310:14)
at Function.NgTools_InternalApi_NG_2.listLazyRoutes (C:\Users\PC\node_modules\#angular\compiler-cli\src\ngtools_api.js:90:31)
at AotPlugin._getLazyRoutesFromNgtools (C:\Users\PC\node_modules\#ngtools\webpack\src\plugin.js:207:44)
at _donePromise.Promise.resolve.then.then.then.then.then (C:\Users\PC\node_modules\#ngtools\webpack\src\plugin.js:443:24)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
ERROR in C:/Users/PC/src/main.ts (1,32): Cannot find module '#angular/core'.
ERROR in C:/Users/PC/src/main.ts (2,40): Cannot find module '#angular/platform-browser-dynamic'.
I am using windows-7 os.When i install and start npm.It is showing the following errors.All the packages have been installed