Faced with a black screen and an inscription "EFI Network 0 for IPv6 Boot Failed"** on a laptop Lenovo when turned on? This error means that the system cannot boot from the network adapter using the protocol IPv6, although you most likely didn't even plan for network booting. The problem is typical for models ThinkPad, Legion, IdeaPad and other brand lines, especially after updating the BIOS, resetting the settings or replacing the hard drive.

In 80% of cases the error is related to incorrect BIOS/UEFI settings or failure in the boot order of devices. Less often, hardware problems are to blame - SSD/HDD failure, damaged connectors, or a conflict with connected devices (for example, a docking station). In this article we will analyze all possible reasons and solutions, including hidden BIOS settings that the manufacturer does not advertise.

Why does the "EFI Network 0 for IPv6 Boot Failed" error occur?

The error appears when the system tries to boot over the network (PXE boot), but fails. This may be a consequence:

  • 🔧 Reset BIOS to factory settings (for example, after removing the battery or updating the firmware).
  • 💾 No boot device — if the SSD/HDD is not detected or damaged.
  • 🌐 Network download priority in the BIOS settings, especially if previously used Wake-on-LAN or network OS installation.
  • ⚡ Conflict with IPv6 - some BIOS versions Lenovo protocol settings are processed incorrectly.
  • 🔌 Nutrition problems - unstable voltage can disrupt UEFI settings.

Most often the error occurs on models with UEFI interface (rather than legacy BIOS), where network boot is enabled by default in the list of boot devices. For example, on Lenovo ThinkPad T480 or Legion Y540 After upgrading an SSD, users encounter this problem due to the fact that the system “forgets” the new drive and tries to boot over the network.

📊 What series is your Lenovo laptop from?
  • ThinkPad
  • Legion
  • IdeaPad
  • Yoga
  • Other

First steps: what to do immediately after an error appears

Before digging into the BIOS settings, follow these basic steps:

  1. Reboot your laptop - sometimes the error is temporary (for example, due to a glitch in the network controller).
  2. Disconnect all external devices: flash drives, hard drives, docking stations, mice. Leave only the power supply.
  3. Check SSD/HDD connection:
    • 🔧 On models with a removable cover (for example, ThinkPad P53) unscrew the bottom panel and make sure that the drive fits tightly in the slot M.2 or SATA.
    • 🔌 If you are using an adapter for M.2 → SATA, try connecting the drive directly.
  4. Reset BIOS hardware way:
    • 🔋 Remove the battery and turn off the power supply.
    • 🕒 Press and hold the power button 30 seconds (discharges the capacitors).
    • 🔄 Connect the power and try to turn on the laptop.

If after these manipulations the error remains, go to the BIOS settings.

☑️ Preparing to enter the BIOS

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BIOS setup: how to remove network boot from priorities

The main reason for the error is incorrect boot order, where the network adapter is located above the hard drive. To fix this:

  1. Enter BIOS/UEFI:
    • 🔄 Reboot your laptop and click F1, F2, Del or Fn+F2 (depending on model Lenovo). There is usually a hint on the screen.
    • 💡 On ThinkPad may need to hold down the button Enter when turned on, and then select BIOS Setup.
  2. Go to section Boot (or Startup on some models).
  3. Disable network boot:
    • 🔌 Find the option Network Boot, PXE Boot or IPv6 Network Stack and set the value Disabled.
    • 📥 In the list of boot devices (Boot Order) move HDD/SSD in first place and EFI Network — to the end or delete it altogether.
  • Save settings (F10 → Yes) and reboot.

    • If after this the laptop still does not boot, check:

    • 🔍 Availability of your SSD/HDD in the list of devices. If it is not there, the problem is with the connection or the drive itself.
    • 🔄 Download mode: for Windows 10/11 must be UEFI (not Legacy).
    • 🛡️ Settings Secure Boot - try turning it off (Disabled).
    What to do if the BIOS does not see the SSD?

    1. Check if your model supports this type of drive (for example, some older Lenovos do not work with NVMe).

    2. Update your BIOS to the latest version - support for new devices is often added.

    3. Try another slot (if available).

    4. If the SSD is new, check it on another PC - it may be faulty.

    Updating BIOS: when is it necessary and how to do it correctly

    If the error appears after updating the BIOS or resetting the settings, the firmware may contain a bug. In this case:

    1. Check your current BIOS version:
      • 🔍 In the BIOS itself (section System Information or Main).
      • 🖥️ B Windows: press Win + R, enter msinfo32 and find the line BIOS version.
    2. Download the latest version from Lenovo website:
      • 🌐 Go to official website, enter your laptop model and find the section BIOS/UEFI.
      • ⚠️ Do not download BIOS from third sites! Risk of getting a brick instead of a laptop.
    3. Update BIOS:
      • 💾 For most models Lenovo just run the downloaded .exe-file from under Windows.
      • 🔧 If the system does not boot, create a bootable USB flash drive with the update utility (instructions are on the Lenovo website).

    Attention! Interrupting the BIOS update process may render the laptop inoperable. Make sure that:

    • 🔋 Battery charge > 50% (or connect power supply).
    • ⚡ No power surges (use UPS if possible).
    • 🖥️ There are no critical tasks on the PC - the update may take up to 10 minutes.
    💡

    If the error remains after updating the BIOS, try rolling back to the previous version. There are usually several firmware versions available on the Lenovo website.

    Checking the hard drive and repairing the bootloader

    If the BIOS sees the SSD/HDD, but there is an error “EFI Network 0 for IPv6 Boot Failed”** remains, the problem may be in:

    • 💽 Damaged Windows bootloader (for example, after an incorrect shutdown).
    • 🗃️ Missing section EFI (happens when manually partitioning a disk).
    • 🛠️ RAW file system (the disk is not formatted or damaged).

    For diagnostics and recovery:

    1. Create a bootable USB flash drive with Windows 10/11:
      • 💾 Use the official one Media Creation Tool.
      • 🔌 Connect the flash drive to the laptop and boot from it (select in Boot Menu, usually F12).
  • Run bootloader recovery: 
    bootrec /fixmbr

    bootrec /fixboot
    

    bootrec /scanos
    

    bootrec /rebuildbcd

    If the commands don't help, try:

    bcdboot C:\Windows /s S: /f UEFI

    (where C: - disk with Windows, S: - hidden EFI-section).

  • Check the disk for errors: 
    chkdsk C: /f /r

    • If the disk is defined as RAW or not visible in Disk Managementyou may need to reinstall Windows or restore partitions using TestDisk.

    💡

    If the error remains after restoring the bootloader, check your Secure Boot settings. On some Lenovo models it conflicts with self-written EFI boot loaders (for example, after installing Linux).

    Hardware problems: when the hardware is to blame

    If software methods do not help, the reason may lie in hardware:

    Symptom Possible reason Solution
    The laptop does not see the SSD, although it is connected Controller malfunction M.2/SATA or the drive itself Try another SSD or connect the drive to another PC
    The error appears only when connecting a docking station Conflict with the external network adapter of the docking station Update the docking station firmware or disable it
    Laptop shuts down a few seconds after error Power problems (bad battery or power supply) Try another power supply, reset the EC controller
    The error appears after replacing the motherboard Incompatibility of BIOS version with new hardware Update BIOS to the latest version

    On models Lenovo Legion And ThinkPad P-series a common problem is memory chip dump (especially if the laptop fell). In this case the error EFI Network may be accompanied by squeaks or blinking indicators. This can only be diagnosed at a service center.

    ⚠️ Attention! If you are not confident in your repair skills, do not disassemble the laptop yourself - there is a risk of damaging cables or contacts. Contact an authorized service Lenovo with a diagnostic error code.

    Prevention: how to avoid mistakes in the future

    To make a mistake “EFI Network 0 for IPv6 Boot Failed”** was not repeated:

    • 🔄 Update your BIOS regularly, but only through official channels.
    • 💾 Do not turn off the power while working with the disc (especially when writing data or updating firmware).
    • 🔌 Use quality SSDs from trusted brands (Samsung, Western Digital, Crucial). Cheap drives often “fall off” from the controller.
    • 🛡️ Create a BIOS backup before experimenting with settings. On some models ThinkPad this can be done through the utility Lenovo BIOS Update.
    • 🌐 Disable IPv6 in Windows Settingsif you don't use it:
      1. Go to Control Panel → Network and Internet → Network and Sharing Center.
      2. Select your connection → Properties → uncheck IP version 6 (TCP/IPv6).

    If you often work with docking stations or external network adapters, add Boot Menu only necessary devices, and unnecessary ones (for example, EFI Network) turn it off completely.

    FAQ: answers to frequently asked questions

    Is it possible to fix the error without entering the BIOS?

    No, because the problem is related to boot settings, which can only be changed through BIOS/UEFI. However, if you have access to Windows, you can try updating the BIOS from under the system (but this does not guarantee a solution to the problem).

    The error only appears when connecting to the network via cable. What to do?

    Most likely it is enabled in the BIOS Wake-on-LAN or network boot priority. Disable the option Network Boot in the BIOS settings and check if your network adapter conflicts with the protocol IPv6 (you can disable it in the connection properties).

    After resetting the BIOS, the laptop stopped seeing the SSD. How to restore?

    Perhaps the reset brought back the settings SATA Mode in RAID or Optane. Go to BIOS and install AHCI. If the SSD is still not visible, check it on another device - it may be faulty.

    Could the error be related to Linux or dual boot?

    Yes. If you installed Linux next to Windows, bootloader GRUB could damage EFI-section. Repair the Windows boot loader via the command line (see section above) or reinstall GRUB from Live CD.

    There is also a “Default Boot Device Missing” error on the screen. What does it mean?

    This confirms that the system does not find the boot disk. Check:

    • Connecting SSD/HDD (physically and in BIOS settings).
    • The presence of an active partition on the disk (you can check via DiskPart team list disk).
    • File system integrity (chkdsk).