Installation Media

Chapter 4 — Creating Installation Media

You've chosen your distro and prepared your machine. Now you need to get Linux onto something you can boot from — a USB stick, a DVD, or in more advanced setups, via the network. This chapter walks through downloading the Linux ISO file, verifying it's genuine, and writing it to installation media. The whole process takes about 15–20 minutes.

1. Downloading the ISO

An ISO file (also called a disc image) is a single file containing the complete contents of a Linux installation disc — the bootloader, the operating system, the installer, and all the software that comes pre-installed. You download one ISO and write it to a USB stick or DVD.

Where to download

Always download from the official website of the distro you chose. Do not trust third-party download sites — there have been cases where tampered ISOs were distributed containing malware.

• Linux Mint — linuxmint.com → Download
• Ubuntu — ubuntu.com → Download
• Fedora — fedoraproject.org → Download Fedora
• Debian — debian.org → Getting Debian → small installation image
• Pop!_OS — system76.com/pop → Download (choose NVIDIA or AMD/Intel)
• Zorin OS — zorin.com → Download (Core edition is free)

Which edition to pick

Many distros offer several editions. The main choices to understand:

• Desktop vs Server — download the Desktop edition unless you're setting up a headless server with no graphical interface.
• 64-bit (AMD64 / x86_64) — this is what almost all modern computers use, regardless of whether they have an Intel or AMD processor. Download this one.
• ARM64 (aarch64) — for ARM-based machines such as Raspberry Pi or Apple Silicon Macs. Only choose this if you know you have ARM hardware.
• LTS vs interim releases (Ubuntu) — choose LTS (e.g., 24.04 LTS) for stability.

Using a torrent

Most distros offer their ISO via torrent as well as direct download. Torrent downloads are often faster (especially for popular distros), resume if interrupted, and are automatically verified against the swarm. If you have a torrent client (qBittorrent is free and reputable), use it — it's perfectly legitimate here.

2. Verifying the ISO

Once downloaded, it's worth verifying that the file wasn't corrupted during the download and hasn't been tampered with. This is done using a checksum — a long string of characters generated from the file's contents. If even one byte is different, the checksum changes completely. The distro's website publishes the expected checksum; you generate one from your downloaded file and compare them.

Finding the checksum on the download page

Look on the same page where you downloaded the ISO for a link that says something like "SHA256SUMS", "Verify your download", or "Integrity check". Download or copy that checksum string — it will look something like:

Verifying on Windows

Open PowerShell (search for it in the Start menu) and run:

The Hash value in the output should exactly match the checksum published on the download page. If they don't match, the file is corrupted — delete it and download again.

Verifying on Linux (from a live session or existing install)

3. Writing the ISO to a USB Stick

You can't just copy the ISO file to a USB stick — the stick needs to be made bootable, which means the ISO's contents are written in a specific way that the computer can start from. Several free tools do this for you.

4. Step-by-Step: Writing with Rufus (Windows)

• 1
  Download Rufus from rufus.ie. Choose the portable version — it's a single .exe file, no installation required. Run it; Windows may ask for administrator permission — click Yes.
• 2
  Insert your USB stick. Rufus will detect it automatically and show it in the "Device" dropdown at the top. If you have multiple USB drives connected, double-check you've selected the correct one.
• 3
  Click "SELECT" next to the Boot selection field and browse to your downloaded ISO file.
• 4
  Partition scheme: Rufus auto-selects based on your system. For modern UEFI computers (most made after 2012) it will choose GPT. For older BIOS/Legacy computers, it will choose MBR. If unsure, leave the auto-selection.
• 5
  Leave everything else at the defaults — file system, cluster size, and volume label don't need to be changed for Linux ISOs.
• 6
  Click START. Rufus will warn you that all data on the USB stick will be destroyed — click OK. The progress bar fills as it writes; this typically takes 3–8 minutes.
• 7
  When the status bar shows "READY" in green, the USB is done. Close Rufus and safely eject the USB stick. It's ready to boot from.

5. Step-by-Step: Writing with balenaEtcher

• 1
  Download and install balenaEtcher from etcher.balena.io. On macOS, drag it to Applications. On Windows, run the installer.
• 2
  Click "Flash from file" and select your downloaded ISO.
• 3
  Click "Select target" and choose your USB stick. Etcher hides internal drives to reduce the risk of accidentally wiping the wrong disk.
• 4
  Click "Flash!" and enter your system password if prompted. Etcher writes the ISO, then automatically verifies the result. Both steps together take 5–12 minutes.
• 5
  When Etcher shows "Flash Complete!" the USB is ready. Eject it safely.

6. Burning to DVD (Optional)

USB is faster, more reliable, and reusable — but if your machine has a DVD drive and no USB ports that work at boot time, a DVD is a valid fallback. You'll need a blank DVD-R or DVD+R disc (not a CD — Linux ISOs are too large).

On Windows

Windows 10 and 11 have built-in ISO burning. Right-click the ISO file in File Explorer and select "Burn disc image". Insert a blank disc, select the correct burner drive, and click Burn. Write speed doesn't matter much — slower (4x) produces more reliable results than maximum speed.

On macOS

Open Disk Utility, go to File → Open Disk Image and select your ISO, then File → Burn to disc.

7. Network Boot / PXE (Advanced)

PXE (Preboot Execution Environment) boot allows a computer to boot from a Linux installer delivered over the network, with no USB stick or DVD involved. The computer requests a boot image from a server on the local network and loads the installer directly into RAM.

This is primarily useful when:

• You're deploying Linux to many machines at once (common in offices and data centres)
• The machine has no working USB ports or optical drive
• You want a centralised install process for a home lab

How PXE boot works (overview)

• The target computer's UEFI/BIOS sends a broadcast DHCP request when set to network boot.
• A DHCP server responds with the address of a TFTP server and the boot file name.
• The computer downloads the bootloader (e.g., PXELINUX or GRUB) over TFTP.
• The bootloader presents a menu; the selected OS image is downloaded over HTTP or NFS.
• The installer runs entirely in RAM.

8. Booting from Your USB Stick

With your USB stick written, the final step in this chapter is to confirm you can boot from it. This is also how you'll start the actual installation in Chapter 5.

The boot menu

Most computers let you choose a temporary boot device by pressing a function key immediately after the power button. The key varies by manufacturer — it's often shown briefly on screen during startup:

• 1
  Insert the USB stick before powering on.
• 2
  Power on (or restart) and immediately press the boot menu key for your manufacturer — usually within the first two seconds of startup. Tap it repeatedly rather than holding it.
• 3
  A boot menu appears listing available devices. Select your USB stick — it may appear as the brand name, "USB HDD", "USB Storage Device", or similar. If you see two entries for the same stick (one with "UEFI:" prefix and one without), choose the UEFI: version on modern computers.
• 4
  The Linux boot menu appears — usually offering "Try" or "Start" (live session) and "Install". For now, choose Try to test hardware compatibility before committing.

Chapter Summary