I upgraded from Win7 32bit to 64bit today by installing 64bit onto a new hard drive and booting into it, and when I reconnected all of my additional hard drives containing just data files, one of them wouldn't display in Computer Management.
It won't display in My Computer at all, and in disk management it displays as a spanned volume that "failed" (as shown in the image) with two partitions. The second partition, 746gb, is the same as the Missing disk shown on the bottom, as far as I can tell.
I've tried everything I can do via right clicking, to no avail: reactivate disk and reactivate volume on the two failed volumes, and New Simple Volume on the unallocated space, and it just pops up a message saying "we recommend that you run chkdsk on this volume after it becomes available for use" and nothing changes.
(I did also try replacing the SATA and power cables, and using a different SATA port just in case, but it's definitely not a cable issue. No change.)
This was not initially a spanned volume at all; I'm not sure why suddenly it started displaying as one when I booted into Windows. It's a 3TB disk and only had one partition on it. Now it's displaying as two partitions, neither of which is accessible.
Google searching revealed that the partition table might have broken or become corrupt or something, but I have no idea how I can fix that. The free data recovery tools I can find online don't recognize the disk at all since I can't actually navigate to it or assign it a drive letter. I can't find any tool to just correct the partition table, and I'd really rather not delete the volumes and format since I have data on the drive.
Any suggestions would be greatly appreciated.