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I can't access my HDD (Drive D).

After having trouble installing Ubuntu on my new EFI system, I couldn't boot either of the OS on my SSD (Drive C). I fixed that problem by running boot-repair, allowing me to boot Windows 8 again. But that created a new problem... I can no longer access my D drive (HDD)... in Windows it says "D is not accessible: The parameter is incorrect."

I tried to format it, but the capacity just says 97 GB when it's really a 2TB HDD.

So I looked it up two ways: in the partition manager on my live USB, and in a program called "GetDataBack for NFTS." They both say that my HDD is an EFI system partition. Is this why I can't access it? Was this done by my boot-repair???

SCREEN CAPTURE: I'm not allowed to post pictures yet so here is the URL to a screen-capture:

I'm concerned mainly with the highlighted partition... the 1st HD with two partitions. (Although I think I screwed up the boot-loader on the 2nd HD which now has 9 partitions.

SO: Can someone tell me if I'm right? I feel like this highlighted partition should NOT be an EFI system partition and that I should somehow convert it back to... whatever it was (LoL). I guess I'll do ext3 or NFTS but I don't remember its original file system. Is this dangerous? Will I screw everything up? What should I do??


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From your description, I guess things are pretty messed up already. If you want to give a try to recover any lost partition then give a try to testdisk utility which is free to download for linux as well as windows. EFI or any other partitioning structure can only be modified on a raw disk without any logical partitioning. If things were working for you previously then EFI is not what is bugging you.

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Can you name a good testdisk utility? – Matt Payne Jan 27 '13 at 2:14
Testdisk is its name. Find it link [link][/link] – Robin Jan 27 '13 at 7:08

I recommend against using TestDisk; that tool is good for recovering deleted partitions, but there's no evidence that any of your partitions have been deleted. I believe you're on the right track that the partition you've highlighted is incorrectly flagged as an EFI System Partition (ESP); however, you should not format (create a new filesystem) on it, since that would destroy any data it contains. Instead, you should set an appropriate filesystem type code on it. You can do this with Linux tools like GParted, parted, and gdisk. The details of how you do this, and the type code you should set, vary with the program and the filesystem that the partition contains. If you'd been accessing that partition from Windows, then it's almost certainly an NTFS volume. You can set it correctly like this:

  1. In Ubuntu, type sudo apt-get install gdisk to install gdisk.
  2. Type sudo gdisk /dev/sda (but the disk might conceivably be /dev/sdb in Linux, in which case you'd need to change that detail).
  3. At the gdisk prompt, type p to view the partition table and verify that you're working on the correct disk -- the ~1.8TiB disk with two partitions. If not, exit by typing q and try another disk device. Partition #2 should show up in gdisk as having a type code of EF00 -- that's gdisk's way of identifying an ESP.
  4. Type t to change a type code. When prompted, enter 2 for the partition number and 0700 for the partition type code (that's the code for FAT and NTFS partitions).
  5. Type p to view the partition table again and verify that it's OK.
  6. Type w to write your changes back out. You'll be asked to confirm this operation.

When you reboot, you should be able to see your disk again in Windows -- at least, assuming that the changed partition type code was the only problem.

One more comment: Since Windows is saying that D: is now much smaller than you expected, my suspicion is that it's mis-identifying one or more of your Linux partitions as unformatted Windows partitions. This is dangerous, since if you were to accept Windows' offer to reformat the partition, you'd trash Linux. You can fix the problem using gdisk in much the way you fixed the misidentified ESP, except that you'd need to figure out which partition(s) hold Linux filesystems and change their type codes from 0700 to 8300.

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