Hello @Joanne Beirne Thank you for reaching out to us on Microsoft Q&A platform. Happy to help!
I understand that you were using MARS agent to backup your on-premise machine which doesn't seem to be active/online due to hardware failure. Now you are looking to restore that machine backed data in Azure to another server.
Please find the answers to your questions:
How can I restore to a diff device?
You can - "Use Instant Restore to restore data to an alternate machine**"
**
Also saying the vault credentials, I saved during config back in 2021 have expired!?
If the vault credential file is invalid (or expired), download a new vault credential file from the sample vault in the Azure portal.
Can I view the backed-up files in Azure portal?
No.
For more information refer to - https://learn.microsoft.com/en-us/azure/backup/backup-azure-restore-windows-server#use-instant-restore-to-restore-data-to-an-alternate-machine
Hope this helps. Please feel free to reply to this post if you need further assistance!
If the response helped, do "Accept Answer" and up-vote it