uable to open: errors were encountered: This file could not be opened.

Hello-

I purchased a Digital Education in 2005. I saved it on either a Mac or PC. I own the book. Now I am trying to open it and I get errors. I cannot even open the notes (comments). I am currently running Windows 7 Ultimate with service pack 1. I apologize for asking the community, this is really a question that should be supported by seller (which I assume is Adobe).

I do have an "ETD" file in the folder with the eBook. The EDT file verifies that I purchased the book and contains my order ID.

Thank you,

Debbie