Bitlocker at Preboot Authentication


  1. Posts : 3
    windows 7 ultimate x64
       #1

    Bitlocker at Preboot Authentication


    I've got a Dell M4400, Win 7x64b Ultimate with bitlocker.
    I unfortunately yielded again to the tweaking demon and upgraded to a SSD.

    Previously, at preboot, I had no option to log in with fingerswipe. I entered a password, it booted, and then I could swipe my finger or enter the Windows password to complete the boot. I also had the option of authentication with the bitlocker key on my usb thumbdrive.

    Now that I've reinstalled the operating system (did not record all of the option choices I made), I have the following problematic behavior at preboot.

    I now have two choices at poweron. screen instructs to swipe finger or press esc to use password.

    If I swipe my finger successfully, I get the windows login screen. here I can swipe or enter a password.

    If I press esc, (as when the printreader doesn't recognize my finger, or if I don't us it at all and just start by pressing esc), I'm told that pre-boot authentication has failed. I then enter password; invariably, at this point, bitlocker requests the entire key, and I can't use the thumbdrive, either.

    Dell premium support punts to Wave; Wave tried then gave up and told me to register more fingers.

    Thanks for ideas. I wonder if there is something that can be done with manage-bde.exe.
      My Computer


  2. Posts : 2,528
    Windows 7 x64 Ultimate
       #2

    When you reinstalled, did you back up your user account or use Windows Easy Transfer to store your current user account before reinstalling on the SSD? Bitlocker is tied to the account that created it (By the windows account ID, not the visible "user name", so you can't just log in and have it work like before if you just created a new user account on the SSD.

    If this is the case, put in the old system disk, and backup or use WET to back up your user account and any other windows settings you want to transfer over, then on the new install, import your old user account and that should hopefully fix the bitlocker issue.
      My Computer


  3. Posts : 3
    windows 7 ultimate x64
    Thread Starter
       #3

    Bitlocker issue


    I used the Intel transfer tool that came with the SSD. But the current system is a rebuild from Dell OEM Windows 7 disk.

    To be clear, I seem to have full access to my files, and when the pre-boot authentication "fails" by pressing "esc" I can finish booting by entering the entire bitlocker key for the SSD.

    It's just that when I press "esc" to choose password entry over fingerswipe at preboot some program (probably WAVE or ControlPoint) flags a boot configuration change to bitlocker.

    BTW, the old drive won't boot on the machine anymore, when I swap drives back, after entering the entire bitlocker key for the old drive, it fails to complete the boot - it crashes.
      My Computer


  4. Posts : 2,528
    Windows 7 x64 Ultimate
       #4

    Ok, so you basically cloned your old drive to the new one and so it's the same user account.

    Well I'm not sure I can help much more... could be that the drive ID was part of the machine hash being used for authentication and now that it's changed it's requiring more from you than before but honestly that's just a blind shot in the dark... :/
      My Computer


  5. Posts : 3
    windows 7 ultimate x64
    Thread Starter
       #5

    Thank you for trying


    Thanks very much for your efforts and ideas.

    Now I have to decide if it's worth decrypting everything, wiping TPM and starting over.
      My Computer


 

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