Wow, what a PITA this issue is, I almost died thinking I lost all my data. I have kind of a weird setup and I had a couple extra steps that enabled me to recover all the data. I also didn't have to deal with recovery of a boot up drive as this is just a massive storage array for media. My setup is an MSI Z68MA-ED55 motherboard using Intel's newest Z68 chipset. I have an 80GB Intel SSD boot drive, a 60GB Crucial SSD cache drive (to accelerate the RAID array), and (3) 3TB disks configured in a RAID5 array. The RAID disks were configured as one, huge GPT/NTFS partion of 5.5TB's usable space in Windows 7 64bit. Here's what I did to recover all my data:
1. Go into Intel RAID BIOS using CTRL-I and delete all non-member disks. I also deleted the 60GB SSD cache drive that I was using for the Z68's special caching and removed it from the array. Basically, I removed all the disks, and deleted the array, and removed the SSD from caching... a blank canvas.
2. Recreate the RAID5 array using the exact same name and settings as the one that was lost.
3. I booted Windows 7 up and used the Intel disk manager to add my 60GB SSD to accelerate the array. Again, used the exact same settings that I did before.
4. This is what tripped me up. I couldn't get the TestDisk program to properly find my partitions, it kept thinking it was a MAC EFS partition. It knew something was there, but I couldn't figure out how to make it work right, and the user interface was bugging me. I had bought Paragon Partition Manager 11 Personal Edition back at some point and had it installed already, so I decided to give it a try. I ran the partition recovery tool and it found the lost partition right off the bat, but wanted to do a lengthy scan of all sectors on the disk, which would have taken hours probably, so I just stopped the scan, right after it found my partition (within a min). Paragon's partition recovery found the 5.5TB partition and saw that 2.5TB's were in use. Hooray I thought! But I wasn't quite there... when I tried to recover it, it claimed it had succeeded, but when I went into the Windows Disk Manager, it showed multiple partitions, which wasn't correct... for some reason it had broken up the disk into multiple partitions which were limited to 2TB. I held my breath, deleted all the partitions in Disk Manager so there was only 5.5TB's of free space. I then converted the disk to a GPT disk. I went back into Partition Manager and re-ran the partition recovery and once again recovered the partition. Voila!!! Windows Disk Manager now saw the whole 5.5TB partition. The last thing I had to do was assign it a drive letter and do a quick chkdsk, which didn't really find any problems. In any case, all my data is back, and my system is now running fine.
Thank you to the original authors of this thread, you got me started on the right track and if it weren't for you I'd be crying right now.