I wanted to post this to help others avoide the 2 hours wasted from my life today dealing with an annoying licensing issue. It appears that new Dell Lattitudes come preloaded with Adobe Acrobat Standard 9. My users, deal with multiple Insurance carrier sites that require Acrobat Reader, which I installed not thinking that another comparable product lurked on the machine "my bad"!.
I received a call for the user saying that when she ran reports rendered in PDF format via Internet Explorer she received an error say the Adobe PDF file could not be opened please open the application accept the license agreement and try again. I tried deleting out registry keys, uninstalling and re-installing reader. Ugrading Internet Explorer from 6 to 7 still no dice. I had to uninstall Acrobat Reader then re-launch the Acrobat standard product. The licensing mode from the 2 products conflict and cause the IE plugin to malfunction. I was surprised to find that Google search I did focused on the registry keys and every instance of Spyware known to humanity.
I've added this question so maybe it will come up that the answer is simply to remove Adobe Reader and register the Acrobat Standard product. Good luck!