C:\Users\User>composer global require "laravel/installer"
Changed current directory to C:/Users/User/AppData/Roaming/Composer
You are running Composer with SSL/TLS protection disabled.
Warning: Accessing packagist.org over http which is an insecure protocol.
Using version ^1.3 for laravel/installer
./composer.json has been updated
Loading composer repositories with package information
Warning: Accessing packagist.org over http which is an insecure protocol.
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- guzzle/guzzle v3.9.3 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- guzzle/guzzle v3.9.2 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- guzzle/guzzle v3.9.1 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- guzzle/guzzle v3.9.0 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- guzzle/guzzle v3.8.1 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- guzzle/guzzle v3.8.0 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- rackspace/php-opencloud dev-master requires guzzle/guzzle ~3.8 -> satisfiable by guzzle/guzzle[v3.8.0, v3.8.1, v3.9.0, v3.9.1, v3.9.2, v3.9.3].
- Installation request for rackspace/php-opencloud dev-master -> satisfiable by rackspace/php-opencloud[dev-master].
Can't install Laravel 5.4 on Windows, I am a beginer at beck-end, so I never worked with composer before, I install php and composer, unpack curl to the root directory, but I have an error.