I had the same problem last year. For your sake, I hope you either printed your earlier returns for yourself, kept pdfs, or at least kept Turbotax copies; if you have a Turbotax copy of your return but no program to open it with, call Turbotax and they can help you with that. If you don't have either, your choices are paying the IRS $50 for EACH copy of ANY earlier return (yes, for a copy of your own return) or doing without. Been there, done that.
I've gritted my teeth and signed up for Intuit's cloud storage of my returns. I hate it, but when you gotta, you gotta.