i ran in a problem using composer for installing/uninstalling some dependencies in laravel which coming back after deleting them from composer.json and deleting the
composer.json
On Window, I see the composer cache file located in C:\Users\{your_user}\AppData\Local\Composer\files
C:\Users\{your_user}\AppData\Local\Composer\files
It stores ZIP files. The below image has 2 Zip files because I have downloaded 2 versions of monolog (1.0.1 and 1.0.2)
To remove the cache, simply delete the Zip file or folder.