Hi Cathy,
Hi, I'm Sumit, here to help with your query on the Microsoft Q&A forum. Apologies for any inconvenience you are experiencing. I am happy to help you today.
The ID doesn't matter; the PC name should match. Do you see your older PC name?
Also, are you sure you had the Windows backup app installed on your older PC, which facilitates backup and restore functionality?
I look forward to your response and am happy to work with you until we find a solution. Please keep me updated.