As your error "cUrl extension not enabled/installed" states, you have not installed or activated the curl extension.
Check your php.ini and search for
;extension=php_curl.dll
and remove the ;
extension=php_curl.dll
Then restart your http server.
If you don't have such an entry, either enter it manually (maybe works if extension is installed) or install it (depending on your host, is it windows/linux?)