I have downloaded Acrobat X pro. Why am I unable to obtain the serial number for this program in my account?

Assuming that you registered Acrobat Pro 10 on Adobe's website, you should be able to use the serial number posted there under your account to reinstall the software.

Exactly what type of message are you getting when you enter the serial number? And can we assume that you licensed Acrobat Pro 10 not as part of an Adobe Creative Suite? If your access to Acrobat is via a license to a version of the Adobe Creative Suite, you need to install Acrobat via the particular Adobe Creative Suite installer, not by a standalone Acrobat Pro 10 installer. Different serial numbers are used.

Assuming that this is not the issue, please note that these forums are not Adobe Customer Support. You will need to contact them directly via “chat” on the website or by phone and reconcile what is going on.

          - Dov