Hi Cole V,
Welcome to Microsoft Q&A!
I understand how frustrating it is to lose three years of Microsoft Solitaire progress due to an inaccessible account and email. Unfortunately, the new game progress is not stored locally, so using USB or copying files will not restore anything.
The old email is likely linked to a Microsoft account. What you needed to do was to try to use it to sign-in to its corresponding Microsoft account, then add the new email as another method to sign in, then remove the old email if possible.
Because the original email is inaccessible and a significant amount of time has passed, recovering that cloud-saved progress is almost impossible. While you can reach out to Microsoft Casual Games | Xbox Support to explore any remaining options, please keep in mind that they generally cannot migrate game data between different accounts, especially with no proof of ownership in your case.
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