Presenter key not accepted after reinstallation

Hi

I had a problem with my Articulate - it kept popping an error prior to publishing. So I following the instructions in the following link and uninstalled both Office and Articulate.

http://www.articulate.com/support/presenter09/kb/?p=2425

Prior to doing this, I noted down my licence key in a notepad. After reinstalling, I tried to activate it and it's not enabling the 'Activate' button. 

Could any of you please help?

Thanks and regards

Sridhar