Boot Issue: Start PXE over IPv4. How to Fix it?

Understanding PXE (Preboot Execution Environment)

What is PXE?

• Definition: PXE is short for Preboot Execution Environment. It is a technology that Intel created, and it allows a PC to start up from software made available over the network rather than from a program stored on the machine itself. In other words, it does away with the need for a local storage device such as a hard drive or an SSD when the computer boots.
• Functionality: The main use of PXE is to roll out operating systems quickly to a lot of machines at once, which makes it a handy tool in a networked setting such as an enterprise office or a data center.

How PXE Works:

• Initiation by BIOS: When a computer is switched on, the BIOS can begin a PXE boot, provided it has been set to look for a network-based boot source before it falls back to the local options.
• Network Requirements: PXE expects a network that has been set up with a DHCP (Dynamic Host Configuration Protocol) server and a TFTP (Trivial File Transfer Protocol) server. Between them, these two servers point the PXE-enabled device toward the correct boot image.
• Process: On startup the BIOS looks for network instructions, talks to the DHCP server to find the TFTP server, and then fetches the boot file from it so that the operating system can be installed or loaded.

Why PXE and Computer Hardware are Discussed Together:

• Integration with BIOS/UEFI: On a modern computer the PXE functionality lives inside the BIOS or the UEFI firmware, and that is what lets the machine reach out to the network even before an operating system has loaded.
• Hardware Dependency: A PXE boot only succeeds when the network interface card, or NIC, supports the PXE standards and has been configured properly to talk to the network boot servers. The hardware has to cooperate.

PXE Use Cases:

• Versatile Deployment: PXE is useful for setting up both client and server operating systems without any physical media at all. It is especially handy wherever systems have to be provisioned quickly, as they often are in a server farm or a development environment.
• Diskless Computers: PXE also lets a diskless computer boot an operating system straight from the network, which suits environments that call for tight security and for software resources to be managed from one central place.

Common Issues and Solutions:

• "Start PXE over IPv4" Message: This message means the computer has tried to boot from the network because it could not find a local boot device. It usually comes down to one of two things, either a BIOS boot order that has been set incorrectly or a problem with the local storage device itself.
• Troubleshooting Steps:
  • Adjust Boot Order: Make sure the BIOS puts the local hard drive ahead of the network boot option.
  • Disable Unnecessary Network Boot Options: In the BIOS, turn off settings such as Network Boot or Wake-On-LAN if you do not actually need them, so the machine stops trying to boot from the network without being asked.
  • BIOS Update: If the trouble keeps coming back, updating the BIOS can clear up the compatibility or firmware problems that sometimes get in the way of a clean boot.

Now that we have gone through what PXE is and the part it plays in booting a system over the network, one thing stands out. Getting the BIOS settings right really is the heart of the matter. The BIOS is what starts a PXE boot in the first place, often because of the way the network has been configured, and that leads us naturally to the practical side of things. The guide below begins with the groundwork, the BIOS settings themselves, which is exactly what you want to look at when you run into a common boot problem such as the "Start PXE over IPv4" message. Here is how to adjust those settings to put the boot process right and to smooth out startup on Windows 11 and Windows 10.

Method 1: Disable Legacy Support and Secure Boot

Turning off Legacy Support and Secure Boot matters because both of these settings can quietly change the order in which your PC looks for something to boot from. Once you have adjusted them, you can be confident the machine is booting from the device you actually intended.

Steps to Disable Legacy Support and Secure Boot

Access BIOS

1. Restart the PC and go into the BIOS setup. On most machines you do this by pressing a particular key, often F1, F2, Del, or Esc, right as the computer starts up.

Modify BIOS Settings

1. Using the arrow keys, move over to the Security tab.
2. Find the Secure Boot option, select it, and set it to disabled.
3. Then move to the Legacy Support option and disable that one as well.

Save and Exit

1. Save the new settings. On most systems you press F10 to save and exit, though on some you may need to go to an 'Exit' menu and pick 'Save changes and Exit'.
2. Leave the BIOS, and confirm any prompt asking you to save the settings.

Post-Changes Actions

Addressing the Boot Order Notification

• When the machine restarts, you may be shown a notice about the change to the boot order:
  1. If it asks you for a display number, type the numbers exactly as instructed. Do not worry when nothing appears on screen as you type, since these digits are deliberately kept hidden.
  2. Confirm what you entered and carry on.

Final Steps

• If the system boots without ever asking for a display number, just let it continue.
• If it does need a bit more attention:
  1. Should the machine still not boot correctly, restart it and go back into the BIOS.
  2. Open the Boot tab and make sure the hard drive is set as the first boot device.
  3. Save the changes and exit the BIOS once more.

Restart Your PC

• Finally, restart the PC so the changes can take effect, and see whether the problem has cleared up.

Method 2: Disable Wake on LAN

If the first method, the one that involved Legacy Support and Secure Boot, did not sort things out, then disabling Wake on LAN is the next thing to try. It is a straightforward change, and in practice it works more often than you might expect.

Steps to Disable Wake on LAN

Preparing to Access BIOS

1. Shut Down Your PC: Power the computer all the way off to get ready for BIOS access.
   • Click the Start menu in the bottom left-hand corner of your screen.
   • Go to the 'Power' options and choose 'Shut Down'.

Entering BIOS

1. Restart and Enter BIOS:
   • Turn the PC on and start pressing the BIOS key straight away to reach the setup. The common keys are F1, F2, F10, Esc, and Del.
   • You will often see a prompt along the lines of "Press ... to enter Setup" as the system starts. Be quick, because that message tends to vanish in a hurry.

Locating and Disabling Wake on LAN

1. Modify BIOS Settings:
   • Once inside the BIOS menu, hunt for the Wake on LAN feature. Where it lives varies from one machine to the next, but you will usually find it under the 'Power Management' tab or the 'Advanced' tab.
   • When you have found the Wake on LAN setting, select it and choose the option to disable it.

Saving Changes and Exiting

1. Save and Exit:
   • Move across to the Exit tab within the BIOS setup.
   • Be sure to save every change before you leave, usually by choosing 'Save and Exit' or by pressing F10.
   • Confirm any prompt to save the settings, and let the computer restart.

Ensuring Success

• After the PC has restarted, watch to see whether it boots correctly this time without reaching for a network boot over PXE. With Wake on LAN switched off, the machine should no longer treat it as a boot source, and that alone often puts an end to the startup trouble.

Method 3: Upgrade BIOS

Upgrading the BIOS on your PC can clear up firmware problems that sit underneath a range of system and compatibility issues. It is an important step, but it is also one to take carefully, because there is genuine risk involved whenever you update a BIOS.

Steps to Upgrade BIOS

Preliminary Checks

1. Identify BIOS Version:
   • Open 'System Information' by typing msinfo into the search field in the bottom left-hand corner of your screen, which is usually reached from the Start menu.
   • Look for the 'BIOS Version/Date' shown under the 'Processor' model, and write it down on paper or save it in a document so you have it to hand.

Determine System Configuration

1. Check System Build:
   • Work out whether your PC was pre-built, sold as a bundle, or put together from separate parts. This is worth knowing, since some BIOS updates are tied to a particular system configuration, and getting it right up front helps you avoid trouble after the update.

Prepare for BIOS Update

1. System Preparation:
   • If you are updating a laptop, make sure the battery is fully charged first. On a desktop, plug into an Uninterruptible Power Supply (UPS) so that a power cut cannot interrupt the update partway through, since an interruption at the wrong moment can corrupt the BIOS.

Download and Install BIOS Update

1. Download BIOS File:
   • Go to your PC manufacturer's support website and find the BIOS update files that match your exact model. Download the newest version, as long as it is more recent than the one you already have installed.
2. Update Process:
   • Follow the manufacturer's own instructions closely. Typically this means running the executable you downloaded, or copying it onto a USB drive and applying the update from within the BIOS setup menu.

Caution and Confirmation

• Backup Important Data: Before you begin the BIOS update, back up anything important as a simple precaution.
• Follow Manufacturer Instructions: Stick closely to the guidance from the device manufacturer, since that is the surest way to keep the risks of a BIOS update to a minimum.

Final Steps

• Once the BIOS has been updated, the PC will most likely restart on its own. Go into the BIOS setup afterward to confirm that the new BIOS version has installed successfully.