Branching to a separate discussion.
Monique28e if you have registered your software title then the serial number will be available at http://www.adobe.com/. You can find details on how to locate your serial number at Find your serial number quickly. I would recommend you try logging in with the Adobe ID/e-mail address you utilized to register your software title.
If you are unsure of the e-mail address that was used to register the software title then please contact our support team directly at Contact Customer Care with alternate e-mail addresses and phone numbers which the software may have been registered under.
If the software title was never registered then I am sorry but we would not have a record of your serial number. Later versions of Creative Suite this was corrected but during the time period of Creative Suite 4 it was necessary to manually register the software title.