ADOBE DIGITAL EDITIONS CANNOT OPEN A PURCHASED EBOOK ON NEW COMPUTER

Hi,

I purchased a book a few months ago and downloaded it on my old computer. It was opened on the Adobe Digital Editions of that computer, which is Authorized without an ID. I am now trying to transfer that book to my new computer but I am not able to do so since there is no account authorized in my other computer that I can link to the new one. Also, I am unable to contact the vendor for a new authorization key. Is there a solution for this? 

Thank you in advanced for your response.