You might try this. I had a similar problem with eCart, and am using xampp. This is what Jason said to do, and it worked.
In your case, edit the wamp php.ini file to enable the cURL extesnion.
in the php.ini file, find the following line:
;extension=php_curl.dll
and change it to:
extension=php_curl.dll
then restart the wamp server.
Hope this helps,
Robert