Why do I have an "Invalid Partition Table"?

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  1. Posts : 18
    Win10Pro-64
       #1

    Why do I have an "Invalid Partition Table"?


    I have a WD 5TB USB drive with backups on it, which I've used for about 9 months (single partition: there was a thing I had to do to overcome the 2.5TB limit that made it incompatible with XP, forgot what but it was about the partition table). It's not bootable; my BIOS is set to first boot from USB, then HD. For 9 months under W7, there has been no problem: the drive was plugged in, the computer booted from the HD, all was well.

    I just upgraded to W10 Pro 64, and that has been okay for about a week -- this included a half-dozen reboots (I think the drive was not attached). I then plugged the drive in and did a backup to that drive; no evident problems (so now W10 knows that this is my backup disk). However after I rebooted, I get a black-screen message at boot-up "Invalid Boot Partition" and that's as far as the machine will go. It's fixable by unplugging the USB drive (it boots from HD), and the drive works after plugging it in.

    I assume the problem has to do with the USB drive. Is there a way to determine what, exactly, is invalid or which partition table is invalid (I'm just assuming it's the one on the USB drive)? And a follow up would be "and how do you fix it"? If anyone has any idea why this happened, please clue me in.
      My Computer


  2. Posts : 3,502
    Win_8.1-Pro, Win_10.1607-Pro, Mint_17.3
       #2

    Easiest: Change your boot order to HDD, CD, USB, Net - boot to HDD first ... all others are security risks

    To see what your machine sees
    1. Download this zip file (contains dmDskmgr-vd.mmc)


    2. Double click dmDskmgr-vd.zip to open the compressed folder
      Double click dmDskmgr-vd.mmc to launch the custom Disk Management console

    3. Press Alt+PrtScn to grab a snapshot of just the Disk Management window
      Open Paint and Ctrl+V to paste it, then save the image

    4. Attach the image to a new post


    Thanks
      My Computer


  3. Posts : 18
    Win10Pro-64
    Thread Starter
       #3

    (What is the security risk in having USB ahead of HD in the boot order?)

    Here's what's on the machine:

    Why do I have an "Invalid Partition Table"?-croppercapture-1-.jpg
      My Computer


  4. Posts : 3,502
    Win_8.1-Pro, Win_10.1607-Pro, Mint_17.3
       #4

    When USB is first, anyone can plug in a USB and boot your machine. Sure they can get to Bios or the Boot Options menu and boot it anyway, but that takes time and a bit of skill (not much)

    You have two Active Partitions, one on each drive ( C: & D: )
    Your USB is initialized GPT ( F: )

    Let's see how the drives are partitioned

    Command Prompt (Admin)
    Enter the following commands:
    diskpart
    lis dis
    lis vol

    sel dis 0
    lis par

    sel dis 1
    lis par

    sel dis 2
    lis par
    exit

    Select all of the text in the Cmd window (right click title bar > Edit > Select all
    Press Enter (copies selected text)

    Paste the text in a new post

    Thanks
      My Computer


  5. Posts : 18
    Win10Pro-64
    Thread Starter
       #5

    Here is the partition table info (I edited out the system chit-chat):

    Disk ### Status Size Free Dyn Gpt
    -------- ------------- ------- ------- --- ---
    Disk 0 Online 465 GB 0 B
    Disk 1 Online 465 GB 0 B
    Disk 2 Online 4657 GB 0 B *


    Volume ### Ltr Label Fs Type Size Status Info
    ---------- --- ----------- ----- ---------- ------- --------- --------
    Volume 0 E DVD-ROM 0 B No Media
    Volume 1 C OS NTFS Partition 453 GB Healthy Boot
    Volume 2 RECOVERY NTFS Partition 11 GB Healthy Hidden
    Volume 3 D SpareHD NTFS Partition 453 GB Healthy
    Volume 4 RECOVERY NTFS Partition 11 GB Healthy Hidden
    Volume 5 F DellBackup NTFS Partition 4657 GB Healthy

    DISKPART> sel dis 0


    Partition ### Type Size Offset
    ------------- ---------------- ------- -------
    Partition 1 OEM 39 MB 31 KB
    Partition 2 Recovery 11 GB 40 MB
    Partition 3 Primary 453 GB 11 GB

    DISKPART> sel dis 1


    Partition ### Type Size Offset
    ------------- ---------------- ------- -------
    Partition 1 OEM 39 MB 31 KB
    Partition 2 Recovery 11 GB 40 MB
    Partition 3 Primary 453 GB 11 GB

    DISKPART> sel dis 2


    Partition ### Type Size Offset
    ------------- ---------------- ------- -------
    Partition 1 Reserved 128 MB 17 KB
    Partition 2 Primary 4657 GB 129 MB


    For good measure, here is what's at the beginning of disk 2. Here is the GPT header (the interpretation as GUID Partition Table -- using Active Disk Editor -- not the raw binary):

    Why do I have an "Invalid Partition Table"?-gpt-header.jpg

    Here are the first two entries (which are followed by a lot of zeros)

    Why do I have an "Invalid Partition Table"?-entries.jpg

    My understanding is that if the disk does not start with a valid JMP instruction, it's not a bootable disk and the Bios should move on to the next disk. (In which case, I would have expected the BIOS to say "nope, not Disk 2, move on to Disk 0", and it wouldn't backtrack to Disk 2. However, I have no idea where in the contorted path to booting it is that this message comes from.

    I will mention that Active Disk Editor reports one additional "thing", a Disk Image:

    Why do I have an "Invalid Partition Table"?-disks.jpg

    The content-interpretation that it gives is:

    Why do I have an "Invalid Partition Table"?-diskimagecontent.jpg

    The "Loaded From..." info corresponds to a System Image backup I did on the 15th (first time under Win10). The thing is, the modified date on the C-drive disk image is 6/17/2016 8:43AM but the remainder of the backup files (the image of the first partition, and the various headers) are all set with modified date as 6/15/2016 6:22PM, which corresponds to when the backup took place. It's odd that the date on the C-drive partition would be changed. I have not previously seen this additional "Disk Image" entity appearing in the Active Disk Editor list, though I spend little time mucking around that close to the metal. The USB drive contains a number of disk images from Win7 system images, which are not showing up in the Active Disk Editor list.

    My goal is to understand what has happened, and why, and I need to know if there is a problem that needs fixing (or is this just a "feature" of Win10). I had a bad experience with restoring a system after a meltdown, and I'd like to avoid a repeat of that.
      My Computer


  6. Posts : 2,324
    Win10
       #6

    Slartybart said:
    Easiest: Change your boot order to HDD, CD, USB, Net - boot to HDD first ... all others are security risks

    To see what your machine sees
    1. Download this zip file (contains dmDskmgr-vd.mmc)
    2. Double click dmDskmgr-vd.zip to open the compressed folder
      Double click dmDskmgr-vd.mmc to launch the custom Disk Management console
    3. Press Alt+PrtScn to grab a snapshot of just the Disk Management window
      Open Paint and Ctrl+V to paste it, then save the image
    4. Attach the image to a new post


    Thanks
    Nice Custom view for Disks Slartybart


    @David , changing the Boot Order should work , though I have no idea why an upgrade to Win10 would cause this unless it handles GPT disks differently eg it sees GPT disks before MBR disks ???

    Laptop HDs are always setup strangely to me with all there recovery partitions etc but it looks like you have two identical disks in it ?
      My Computers


  7. Posts : 18
    Win10Pro-64
    Thread Starter
       #7

    Disk 0 is an SSD, cloned from spinning disk = Disk 1 (both same size), where I then re-formatted the spinning disk 'cuz one shouldn't have two active partitions at the same time at bootup. So partitions 1 and 2 on both internal drives are the same in size, and probably much content (especially the Dell Recovery partition which is the first partition on both), but there are various differences in the partition tables like start head, end head, serial number. Except yikes I now see that the second partitions of both Disk 0 and Disk 1 are flagged as active, though only the third = C-drive is reported as "Boot". So I may be confused about these flags, or what the rules are. I'm halfway sure I checked this 9 months ago when I first got the machine and moved the OS to the SSD, but maybe I just followed the "if it works, just be grateful" rule.
      My Computer


  8. Posts : 2,324
    Win10
       #8

    Yes I noticed the two active partitions too and wondered if you were using imaging software to do a full backup/clone to the 2nd disk , as long as the boot order is correct in the bios it should boot off the SSD , it being found 1st , some bios's have a HDD and CD/DVD boot order as well as a standard boot order too though so maybe worth checking.

    This boot issue happens to me too if I leave the USB as 1st boot item , and it isn't bootable , eg if my Probox is turned on , it is backups/storage only so not bootable, so I just have to remember to switch the bios back after using a bootable USB Drive for something.
      My Computers


  9. Posts : 353
    Multi-Boot W7_Pro_x64 W8.1_Pro_x64 W10_Pro_x64
       #9

    DavidOdden said:
    Except yikes I now see that the second partitions of both Disk 0 and Disk 1 are flagged as active, though only the third = C-drive is reported as "Boot". So I may be confused about these flags, or what the rules are.
    In Windows Disk Management the Boot partition is the partition Windows is running from.
    That is the partition where Windows is installed, and running from.

    Having multiple Active partitions can cause problems.
    I don't see a System partition in the screen print in post #3.
    I'm not sure where your bootloader is, it's normally the System, Active partition for a MBR Legacy BIOS PC.
    You don't have a EFI partition, so i don't think you have UEFI.
      My Computer


  10. Posts : 353
    Multi-Boot W7_Pro_x64 W8.1_Pro_x64 W10_Pro_x64
       #10

    In the screen print in post #3 the lower pane does not show what partition is on what disk.
    I don't know why.
    For me in DM the partitions are displayed in the lower pane, so i know what partition is on what disk.
    Your lower pane is not something i understand.
      My Computer


 

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