I'm coming here and asking a question that has been already answered in another post, but all the solutions don't work. So, I'm creating a new angular2 app from the quickstart folder of angular website.
I've done npm install and all is okay, I have my node_modules folder at the root.
But, when I'm doing ng serve, this is the error I got :
ERROR in angular/src/app/app.component.ts (1,27): Cannot find module '@angular/core'.
ERROR in angular/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 angular/src/app/app.module.ts (1,31): Cannot find module '@angular/platform-browser'.
ERROR in angular/src/app/app.module.ts (2,26): Cannot find module '@angular/core'.
ERROR in angular/src/app/app.module.ts (16,14): 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 angular/src/main.ts (1,32): Cannot find module '@angular/core'.
ERROR in angular/src/main.ts (2,40): Cannot find module '@angular/platform-browser-dynamic'.
This is my folder structure :
And this is my tsconfig.json :
{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "moduleResolution": "node",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "lib": [ "es2015", "dom" ],
    "noImplicitAny": true,
    "suppressImplicitAnyIndexErrors": true,
    "typeRoots": [
      "../node_modules/@types/"
    ]
  },
  "compileOnSave": true,
  "exclude": [
    "node_modules/*",
    "**/*-aot.ts"
  ]
}
Edit :
This is my app.module.ts :
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

