I installed laragon full 3.1.6 successfully in the first time 2 weeks ago and works fine with laravel project.
For some reason I uninstalled laragon and reinstalled again then
λ php composer.phar
Could not open input file: composer.phar
I clean up any files about laragon, laravel and composer etc, and reinstalled a few times. But it still happened above.

files auto store
C:\laragon\bin\composer\composer.phar

after install laravel composer auto store
.\AppData\Local\Composer
.\AppData\Roaming\Composer

windows 10

Thanks for any help!