On what platform/OS? What do you mean by does not work? Did you reenter the SN and such when you installed it? Does Acrobat open at all (this is related to the question about does not work)? If so, then go to Help and do the updates. If you can't open Acrobat at all you can try the following (Windows assumed):
1. Go to Start>Control Panel>Programs & Features (or the equivalent), select Acrobat, and do a repair.
2. Download the updates from http://www.adobe.com/support/downloads/product.jsp?product=1&platform=Windows and install the updates in order (unless indicated where you can skip -- downloading from the last to the oldest will let you know which you can skip). You only need to reboot after the last update.
Something similar will likely work on a MAC.