Tell me what can be the problem ??"problems" may be that You have missing the file "composer.phar" who in fact is an executable file composer a. If You have
In the environment variables all spelled outso, PHP should properly be called the command "php" or "php -v". If so - it's small, You just need to find where the file "composer.phar" and call it via PHP like this:
php composer.pharand then write the desired command, for example:
php composer.phar create-project ...