MyBook 3TB Drive Suddenly shows as uninitialized -- any hope?

I have a 3TB MyBook external USB drive that contained around 50 iso files. Never had an issue with it until the other day when it disappeared from the “This PC” display on the Win7 machine it’s connected to. When i opened the Disk Management tool, I see the drive listed, but it says it’s “Uninitialized”. I have not initialized it fearing this would end any chance of recovering the data.

Any ideas on how I might go about recovering the ISO files on this drive? Any tips are greatly appreciated. Thanks!