I've had a Windows Server 2012 Essentials machine (6 drives + 1 external USB 3TB dedicated backup) running fine for over a year now. The system backup was configured through the Essentials Dashboard, the backup drive was found automatically by Windows without any custom drivers, and was successfully backing up as scheduled. A few days ago, the server rebooted for an update, and started blue-screening early on during the boot. Using the install media, I went to the restore facility, but the dedicated external USB backup drive isn't being found (the restore list is empty). I tried using other USB ports (they all work, as tested with the keyboard), but the backups on it still aren't showing. Moving the backup drive to a nearby Windows 8.1 machine, it shows up correctly in the Disk Manager (the name is correct; no drive letter assigned, as expected). From the system-recovery command-line on the server, wbadmin get drives show it, but as [not mounted].
What should my next steps be? Is it safe to mount it to a drive letter on the Windows 8.1 machine and share it out, or will that irreparably damage the backups? Is there something obvious I'm missing? Why isn't the Windows Server 2012 Essentials install media's repair functionality finding it (this should be a no-brainer, right?)?
The drive in question is a Seagate model SRD00F2.
Thanks!