Hi there,
If you have purchased the serial number for Captivate 7 English version, then that will be valid on English version.
You cannot use that serial number on Spanish version of Captivate 7.
You need to contact Adobe Support and provide your serial number or subscription details, and then we will be able to check whether you have the English version or Spanish.
And we will then check whether you will be able to switch from English version to Spanish or not.
Please contact us on:http://helpx.adobe.com/contact.html?product=captivate or tcssup@adobe.com
Thanks.