I had a Windows 8.1 that required a re-install. In the process, my 4TB secondary disk is now showing up in Disk Management as an EFI System Partition, with no volume.
In DISKPART, a volume is shown, with the info as "Hidden".
In MiniTool Partition Wizard the volume is shown as an EFI System Partition, but it's NOT listed as hidden. Using the tools in that software, I can successfully browse the data, etc. I've tried hiding, then unhiding the partition, without success.
So, my question is:
How can I convert this EFI System Partition back into an ordinary data partition that I can access and use?
(Unhide a EFI System partition doesn't help because my partition isn't flagged as hidden.)