I would remove the S/N from your post, but I don't have that authority. Please, never post a S/N on a public site. If you can remove it, please do. At this point, if you succeed in getting it deactivated (should be on the help menu), you may find someone else has grabbed your S/N and is using the product. I don't know how Adobe might treat that.
If you have deactivated, then uninstall and whether successful or not run http://labs.adobe.com/downloads/acrobatcleaner.html. If you are on a MAC, the latter might not work.