Class 'Collective\Html\HtmlServiceProvider' not found in laravel 5? - laravel-5.1

Question

i currently installed laravel and trying to create my first app, however when i required the laravel collective i get error above.
here is my composer.json
{
"require": {
"laravel/installer": "~1.1",
"laravelcollective/html": "5.1.*"
}
}
and my app.php have these lines..
providers=>
...Illuminate\Validation\ValidationServiceProvider::class,
Illuminate\View\ViewServiceProvider::class,
Collective\Html\HtmlServiceProvider::class,
aliases=>
...'Validator' => Illuminate\Support\Facades\Validator::class,
'View' => Illuminate\Support\Facades\View::class,
'Form' => Collective\Html\FormFacade::class,
'Html' => Collective\Html\HtmlFacade::class,
i've been reading and searching for solutions but currently they never worked for me.. any help will be appreciated.. thanks in advance..
UPDATE
this is my cmd as of now..

Answer 1

u have to use php artisan serve inside your project folder. not inside composer folder.
for eg, laravel is my project folder inside www directory,
so, f:/wamp/www/laravel> php artisan serve

Answer 2

Here are the steps I took to install it in my app in Laravel 5.1.
I would suggest you delete the vendor folder for this from your vendor files and remove that line from your composer.json file to start from scratch.
First, require the package:
composer require "illuminate/html":"5.0.*"
Next, add it to your providers:
'providers' => [
...
'Illuminate\Html\HtmlServiceProvider',
],
Finally, add it to your aliases:
'aliases' => [
...
'Form'=> 'Illuminate\Html\FormFacade',
'HTML'=> 'Illuminate\Html\HtmlFacade',
],
You can check to see if it has worked by doing the following:
1) php artisan tinker
2) > Form::text('foo')
Which should output "<input name=\"foo\" type=\"text\">"

Answer 3

It seems like you have installed the HTML package and you are trying to use it in your "old" laravel app.
If you install a new app using the composer it should work fine, but if you are trying to use it in your "old" app that you created before installing the form/html collective try to download the files and copy the files in the src folder to the config folder in your app and you are good to go.