reinstall Adobe Acrob XI on PC asks to register but thinks computer is offline

hard disk failed, so just a reinstall of existing product adobe acrobat XI, which was previously registered from old PC. program prompts to "register" or "skip".  if i click register, there is an error message saying the computer is not on line and to contact customer support. clearly the computer is on line b/c i am typing this now on the very same computer.

do i have to re register the product?  how do i do this if it thinks the computer is not connected to the internet?  and if the product is already registered from the original purchase, how do i make this register window go away?

thank you!