composer install错误提示：'composer' is not recognized as an internal or external command, operable program or batch file.
E:\phpstudy\PHPTutorial\tools\composer>composer install
Composer could not find a composer.json file in E:\phpstudy\PHPTutorial\tools\composer
To initialize a project, please create a composer.json file as described in the https://getcomposer.org/ "Getting Started" section
E:\phpstudy\PHPTutorial\WWW\my>composer install
'composer' is not recognized as an internal or external command,
operable program or batch file.
我的项目目录：E:\phpstudy\PHPTutorial\WWW\my 两种安装都不行，请问？？？
