Error when tried to do composer install in laravel 5 project

I try to do $ composer install to install the dependencies in a Laravel 5 project, but i got this error

$ composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for intervention/image 2.3.4 -> satisfiable by intervention/image[2.3.4].
    - intervention/image 2.3.4 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.

I've heard some folks say about adding something in your PHP.ini file, but i don't know which PHP.ini should be configured, since i have 2 PHP.ini file, 1 in xampp and 1 in IISEXPRESS. I dont know how to solve this problem, please any help would be appreciated. Thanks.

via Chebli Mohamed