AWS with Laravel 4 Missing curl

Question

I'm trying to install aws service provider s3 for laravel 4. (still learning :D) I referred to this: https://github.com/aws/aws-sdk-php-laravel/tree/1.0 and followed the readme.md instructions but I stopped at composer update.

I got this error:

I checked the curl is already enabled in my wampserver. I also followed this: http://amitavroy.com/justread/content/articles/uploading-images-aws-s3-laravel-application but failed. Anyone has idea what to do?