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BIOS update failure & recovery

From BIOS Update Disaster to Bootable Bliss: A Dell Precision 7670 Recovery Saga🔗︎

TL;DR🔗︎

A Dell BIOS update on a Precision 7670 corrupted the system's boot configuration, causing it to fail at startup with BSOD errors 0x0000225 and 0xc0000098. The fix required a multi-step process: manually clearing a corrupted boot list in the BIOS filled with duplicate entries, manually creating a new boot option for a Windows 11 USB drive, loading the Intel VMD (IRST) driver to make the RAID array visible to the installer, and finally, using the bcdboot command from the Command Prompt to rebuild the bootloader without losing any data. The specific command used was bcdboot E:\windows /s S: /f UEFI. The machine is now fully functional.

The Initial Crisis: A BIOS Update Gone Wrong🔗︎

It all started, as many IT nightmares do, with an update. It seems every Dell firmware update is a regression on the last, so I kept putting off the updates. This round of updates included a BIOS update (1.32.0), released 17th September 2025, coupled with some driver firmware updates, plunged a powerful Dell Precision 7670 workstation into a boot loop from which it seemed there was no escape.

The initial symptoms were alarming: * A blank screen for about 5 minutes. * The Dell logo remaining for about 5 minutes (DELL) "Secured with Dell SafeBIOS." * Eventually restarting, repeating the cycle.

Initial attempts to use Dell's BIOS recovery options were met with frustration. While "Load BIOS Defaults" briefly restored access to Windows, a subsequent restart (which presumably re-applied the problematic BIOS update) brought the system back to its broken state.

Accessing BIOS Recovery

  1. Turn off computer.
  2. Unplug power lead.
  3. Press Ctrl + Esc.
  4. Plug in the power lead until the keyboard lights up.
  5. Release the keys.

This time, the system presented various flavors of the dreaded Blue Screen of Death (BSOD) during the boot process: * Recovery Error Code: 0x0000225 - "A required device isn't connected or can't be accessed." This suggested a problem with the boot drive or its accessibility. * Recovery Error Code: 0xc0000098 - "The Boot Configuration Data file doesn't contain valid information for an operating system. File: \BCD." This was a more specific indicator of a corrupted boot configuration.

Attempts to access the Windows Recovery Environment (F1, F8) or UEFI Firmware Settings (Esc) from these BSODs simply looped back to the Recovery screen. Even a re-attempt at the Dell BIOS recovery (Ctrl + Esc + Insert power adapter) yielded only a diagnostic red/green/blue screen sequence, confirming deeper firmware corruption.

The Search for a Bootable Solution: USB Woes🔗︎

The immediate challenge was to boot from external media to access recovery tools. A bootable Windows 11 USB SSD was prepared using Rufus (configured for GPT/UEFI/FAT32), but the laptop steadfastly refused to list it in the F12 One-Time Boot Menu.

Initial troubleshooting in the BIOS (F2) revealed: * Boot Mode was UEFI only. * Secure Boot was initially enabled, then temporarily disabled as a troubleshooting step, but didn't resolve the USB detection. * USB Boot Support was enabled. * Thunderbolt Boot Support was disabled.

The laptop's configuration, with one USB-A and multiple USB-C/Thunderbolt ports, added to the confusion. Despite USB Boot Support being enabled, the USB-A port still didn't register the boot drive. The decision was made to enable Thunderbolt Boot Support and attempt booting from a USB-C/Thunderbolt port.

BIOS Shenanigans: Duplicate Entries and Manual Intervention🔗︎

Even with all relevant boot support enabled, the USB drive wouldn't appear in the F12 boot list. However, a crucial finding was made within the BIOS's Boot Configuration section. While the USB drive wasn't listed, the "Add Boot Option" feature allowed browsing the file system, and the USB drive's contents were visible!

This confirmed the BIOS could 'see' the drive but was failing to auto-register it. The \efi\boot\bootx64.efi file was the target. However, adding it manually initially failed with "Invalid File" errors, User/bad UI error: Make sure the file is selected and appears in the box below.

Further investigation into the Boot Configuration revealed the root cause of the BIOS's confusion: a massive list of eight duplicate entries for the internal Samsung 990 Pro SSDs. The Dell Precision 7670 was configured for a RAID 1 array, and while the RAID array itself was reported as "Healthy" in the Intel Rapid Storage Technology (IRST) utility (accessed via F12 -> Device Configuration), the BIOS's boot list was severely corrupted by the update. This overload of invalid boot entries was preventing new, valid entries (like our USB drive) from appearing.

The critical step was to delete all duplicate Samsung 990 Pro entries from the BIOS Boot Sequence list. This freed up space and cleared the confusion. Immediately after deletion, the "Add Boot Option" was used again, pointing to \efi\boot\bootx64.efi on the USB drive, and named "USB_BOOT". This time, it was successfully added and moved to the top of the boot order.

The Drive Disappears: Intel Rapid Storage Technology (IRST) Driver to the Rescue🔗︎

With the "USB_BOOT" option now functional, the laptop finally booted into the Windows Setup environment. However, upon reaching the "Where do you want to install Windows?" screen, a familiar message appeared: "We couldn't find any drives."

This is a classic hurdle for modern Intel systems running in "RAID On" mode with Intel VMD (Volume Management Device) controllers. The Windows installer lacks the necessary Intel Rapid Storage Technology (IRST) drivers to see the RAID array.

The solution involved:

  1. Downloading the latest IRST driver from Dell's support site (for the Precision 7670).
  2. Extracting the driver files onto the bootable USB drive.
  3. Back in the Windows Setup, clicking "Load driver", browsing to the VMD folder within the extracted IRST drivers.
  4. Selecting the "Intel RST VMD Managed Controller 09AB (iaStorVD.inf)" driver.

Once loaded, the installer successfully displayed the RAID volume and its partitions.

The Final Fix: Rebuilding the Boot Configuration Data (BCD)🔗︎

With the drives now visible, the path was clear to repair the corrupted Boot Configuration Data (BCD).

  1. Accessing Command Prompt: From the Windows Setup screen (after loading the IRST driver), press Shift+F10 to open the Command Prompt.
  2. Identifying Partitions: Run diskpart and list volume in the Command Prompt,:
    • Volume 2 (1862 GB, NTFS) was the main Windows installation (assigned E:).
    • Volume 3 (100 MB, FAT32) was the EFI System Partition (ESP), which needed a drive letter assigned.
  3. Assigning EFI Drive Letter: The command select volume 3 followed by assign letter=S assigned a temporary drive letter S: to the EFI partition.
  4. Exit diskpart: diskpart> exit Enter

  5. Rebuilding the BCD: Finally, the bcdboot command was executed:

    bcdboot E:\windows /s S: /f UEFI`

    This command copies the essential boot files from the Windows installation on E: to the EFI System Partition on S:, creating a clean and correct bootloader for the UEFI firmware. A warning message about failing to remove duplicate bootmgr objects appeared (Status = [c0000225]), but the critical message "Boot files successfully created." confirmed success. 6. Exit Command Prompt exit Enter 7. Close "Windows Setup". This reboots the computer. Remove the USB drive.

Resolution: Back in Windows!🔗︎

Upon restarting the Dell Precision 7670 (and removing the USB drive), the system successfully booted directly into Windows. The combination of understanding the BIOS's limitations, manually managing boot entries, loading necessary drivers, and rebuilding the BCD proved to be the comprehensive solution to recover this workstation from a debilitating BIOS update.

Key takeaways for any IT professional encountering similar issues:

  • Always verify RAID health before attempting destructive fixes.
  • BIOS boot lists can become corrupted by updates, requiring manual cleanup.
  • IRST drivers are often essential for Windows installers to see RAID volumes on modern Intel platforms.
  • bcdboot is a powerful tool for repairing UEFI boot configurations without data loss.

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