Unable to upload video files in drupal 7 with the video module
According to your error, you need to have CURL installed.

If you're running a mac:
http://www.davidonzo.com/lng/en/post/986/php-mac-os-x-how-to-install-the-curl-library/

If you're running linux:
type in the command line - "apt-get install curl"

If you're running WAMP on Windows:
click the WAMP icon in task tray, then go to PHP > PHP Extensions > php_curl. Then restart apache.