Laravel 5.1 error in installation on windows 7 using xampp

Hi can anyone help me to install laravel 5.1 on windows 7 using xampp? but in failed when im creating project, i already installed my composer

Error response

composer create-project laravel/laravel blog1 "5.1.*"
  Installing laravel/laravel (v5.1.11)
   - Installing laravel/laravel (v5.1.11)
   Loading from cache

Created project in blog1
  > php -r "copy('.env.example', '.env');"
  > php artisan clear-compiled

Warning:require(C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php): failed to open stream: No such file or directory in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17

Fatal error: require(): Failed opening required 'C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17

PHP Warning:  require(C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php): failed to open stream: No such file or directory in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17
PHP Fatal error:  require(): Failed opening required 'C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17
Script php artisan clear-compiled handling the pre-update-cmd event returned with an error

[RuntimeException]
Error Output: PHP Warning:  require(C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php): failed to open stream: No such file or directory in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17

PHP Fatal error:  require(): Failed opening required 'C:\xampp\htdocs\blog1\bootstrap/../vendor/autoload.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\blog1\bootstrap\autoload.php on line 17


create-project [-s|--stability STABILITY] [--prefer-source] [--prefer-dist] [--repository REPOSITORY] [--repository-url REPOSITORY-URL] [--dev] [--no-dev] [--no-plugins] [--no-custom-installers] [--no-scripts] [--no-progress] [--keep-vcs] [--no-install] [--ignore-platform-reqs] [--] [<package>] [<directory>] [<version>]

via Chebli Mohamed