Flashing Ubuntu 25 on a Dell Laptop

This guide provides a comprehensive walkthrough for installing Ubuntu 25 on Dell laptop hardware, with a specific focus on the critical BIOS configurations required for a successful installation.

1. Prerequisites

Before starting the process, ensure you have prepared the following:

  • A USB flash drive with at least 12GB of capacity.
  • The Ubuntu 25 ISO image (available from the official Ubuntu releases page).
  • A full backup of your existing data, as this process may involve disk formatting.

2. Creating the Bootable Media

To begin, you must create a bootable USB drive using the ISO file.

2.1 Using BalenaEtcher

  1. Download and launch BalenaEtcher.
  2. Select the downloaded Ubuntu 25 ISO.
  3. Select your USB drive.
  4. Click Flash! and wait for the process to complete.

2.2 Using Terminal (CLI)

If you prefer the command line, identify your USB drive using lsblk and use the dd utility:

# Replace /dev/sdX with your actual USB device path
sudo dd if=ubuntu-25-desktop-amd64.iso of=/dev/sdX bs=4M status=progress oflag=sync

3. Configuring Dell BIOS Settings

Dell laptops require specific BIOS/UEFI adjustments to recognize the installer and the internal storage correctly.

3.1 Accessing the BIOS

  1. Restart your laptop.
  2. Repeatedly tap the F2 key as soon as the Dell logo appears.

3.2 Storage Configuration (SATA/NVMe Mode)

By default, many Dell laptops are set to ‘RAID On’. Ubuntu generally requires AHCI mode to detect internal SSDs.

  1. Navigate to System Configuration > SATA Operation.
  2. Change the selection to AHCI.
  3. Apply the changes.

3.3 Secure Boot

While modern Ubuntu releases support Secure Boot, disabling it during installation can prevent common driver conflicts.

  1. Navigate to Secure Boot > Secure Boot Enable.
  2. Select Disabled.

3.4 Fast Boot

  1. Navigate to POST Behavior > Fastboot.
  2. Set it to Thorough to ensure all USB ports and hardware are initialized before booting.

4. Booting and Installing

  1. Insert the USB drive and restart the laptop.
  2. Tap the F12 key repeatedly to enter the One-Time Boot Menu.
  3. Select your USB drive under the UEFI Boot section.
  4. When the GRUB menu appears, select Try or Install Ubuntu.
  5. Once the desktop loads, open the installer and follow the wizard instructions for partitioning and user setup.

5. Post-Installation Steps

After the first boot, update your system to ensure all hardware drivers are current:

sudo apt update && sudo apt upgrade -y

Source: GitHub Issue #25 | Contributor: @coltonchrane

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