What Is Ubuntu Live USB? Complete Beginner’s Guide to Creating, Using, and Persisting Ubuntu Without Installation

1. Introduction: What Is Ubuntu Live USB?

Many people want to try installing a new operating system on their computer, but hesitate because they worry, “What if my current Windows environment gets erased?” or “The installation process looks complicated and risky.”
In such situations, a very useful solution is “Ubuntu Live USB”, which allows you to boot Ubuntu directly from a USB flash drive.

Basic Concept of Ubuntu Live USB

An Ubuntu Live USB contains a complete Ubuntu system stored on a USB flash drive, allowing a computer to boot directly from it.
Unlike a standard OS installation, it runs Ubuntu temporarily from the USB drive without modifying the contents of the internal hard disk or SSD.

• You can try Ubuntu without deleting your existing Windows or macOS system
• Because it barely modifies the host computer, it is very safe
• By carrying the USB drive, you can boot the same Ubuntu environment on different PCs

Thanks to these features, Ubuntu Live USB is ideal for users who want to “get a feel for Ubuntu first” or “check whether an old PC can run Ubuntu smoothly.”

Why Ubuntu Live USB Matters Today

In recent years, there has been growing interest in reusing low-cost laptops and older PCs.
However, formatting a disk and installing Ubuntu right away involves risk, and this can be especially problematic on work computers or shared family PCs.

With Ubuntu Live USB, you can:

• Try Ubuntu on a work PC during free time without installing it
• Check whether an older PC runs Ubuntu smoothly before installation
• Use it as an emergency boot environment to recover data from a PC that no longer boots

It successfully balances two conflicting desires: “I want to try Ubuntu” and “I don’t want to break my current environment.”

What You Will Learn in This Article

This article is written for beginners who have never used Ubuntu Live USB before. It explains the following step by step:

• The basic mechanism and features of Live USB
• What you need to prepare to create an Ubuntu Live USB
• The full process from creation to booting, along with important precautions
• An overview of “persistence,” which allows settings and files to be saved
• General troubleshooting approaches if the system does not boot properly

Each topic is explained clearly and in order.

2. Advantages and Use Cases of Live USB

Ubuntu Live USB is not just a system that “boots Ubuntu from a USB drive.”
It offers many advantages, including safety that does not damage your existing environment and the convenience of portability.
Here, we will organize these benefits and explain real-world situations where Live USB is especially useful.

Main Advantages of Live USB

1. Experience Ubuntu Without Installation

The biggest advantage of Ubuntu Live USB is that it allows you to boot Ubuntu without modifying the internal storage of your PC at all.
You can keep your existing Windows or macOS environment intact while checking Ubuntu’s usability, performance, and application behavior.

2. Almost Zero Impact on the Existing OS

Unlike installation-based setups, Live USB runs entirely from the USB drive.
The risk of data loss or partition damage due to operational mistakes is very low, making it safe even for beginners.

3. Carry “Your Own Linux Environment” on a Single USB Drive

By carrying a Live USB, you can easily recreate the same Ubuntu environment on compatible PCs.
This flexibility allows you to use Ubuntu anywhere—at home, in a lab, or on a secondary PC.

4. Use It as an Emergency Recovery Tool During System Failures

If Windows or Ubuntu installed on the internal disk fails to boot, a Live USB allows you to start the PC externally and recover data.

• Copy files from the internal disk
• Check boot settings
• Repair corrupted files

5. Test and Extend the Life of Older PCs

Many users want to check whether an old laptop can run Ubuntu properly.
With Live USB, you can boot Ubuntu first and decide whether to install it later.

Practical Use Case Examples

● Beginners Who Want to “Try Ubuntu First”

If you are interested in Linux but feel that it might be difficult or intimidating, Live USB is the perfect starting point.

● Work or School PCs Where Installation Is Not Allowed

Even if you do not have administrator privileges and cannot install an OS, Live USB can still be used as long as USB booting is permitted.

● Engineers Who Want the Same Work Environment While Traveling

By enabling persistence for development tools and settings, Live USB becomes a highly convenient portable Linux environment.

● Data Recovery When a Desktop or Laptop Fails to Boot

OS boot failures are not uncommon.
Having a Live USB significantly lowers the difficulty of recovery in emergency situations.

● Users Who Want to Revive an Old PC Temporarily

If the system runs smoothly in live mode, you can later install Ubuntu and reuse the PC as a lightweight Linux machine.

Ubuntu Live USB offers value far beyond a simple “trial tool,” ranging from everyday use to serious emergency recovery.

3. Required Items and Important Precautions

Before creating an Ubuntu Live USB, let’s organize the necessary equipment and key points to check in advance. Understanding these will significantly reduce problems and confusion during the creation process.

What You Need

● USB Flash Drive (Recommended: 16GB or More)

The Ubuntu ISO image is several gigabytes in size, and additional space is required to run it as a live environment.
At least 8GB is required, but 16GB or more is recommended for better stability and for using persistence.

● A PC for Writing the USB (Windows / macOS / Linux)

A Live USB can be created from any operating system.
Windows users are the most common, and many easy-to-use tools are available, making the process particularly simple.

● Ubuntu ISO Image

Download the ISO image from the official Ubuntu website.
In addition to the standard version, there is also a “Japanese Remix” with preconfigured Japanese language support.

• Official Ubuntu Website
• Ubuntu Japanese Team (Japanese Remix)

Either option works fine, but the Japanese Remix is convenient if you want Japanese language support from the start.

● USB Writing Software

The available tools differ by operating system, but any of the following can be used:

• Rufus (Windows) – Fast and very easy for beginners
• balenaEtcher (Windows / macOS / Linux) – Simple and resistant to mistakes
• UNetbootin – Lightweight and multi-platform

For Windows environments in particular, Rufus is the standard choice and rarely fails.

Important Precautions to Check in Advance

● All Data on the USB Drive Will Be Erased

Creating a Live USB completely formats the USB flash drive.
Be sure to back up any important data beforehand.

● USB Quality and Speed Affect Performance

Older or low-cost USB drives often have slow read/write speeds, which can make Ubuntu boot slowly and applications feel sluggish.

If possible, choose:

• USB 3.0 or newer
• Products from well-known manufacturers

● Check Whether USB Boot Is Enabled in BIOS/UEFI

On some PCs, booting from a USB device is disabled by default.

• Boot Mode (UEFI / Legacy)
• Secure Boot enabled or disabled
• Boot Priority (boot order)

Checking these settings in advance will save you time and stress later.

● If It Doesn’t Boot, the Cause Is Often the PC, Not the USB

When Live USB fails to boot, it is easy to assume the USB drive is faulty, but in reality, common causes include:

• Secure Boot enabled
• Mismatch between UEFI and Legacy mode
• Poor contact or issues with the USB port

● Persistence Is Not Supported by All Tools

As explained in later sections, “persistence” allows you to save settings and files.
However, not all USB creation tools support this feature.

If you plan to use persistence, choose a supported tool such as Rufus.

Carefully checking these points during preparation is essential for a smooth Live USB experience.

4. Steps: How to Create an Ubuntu Live USB

In this section, we explain the actual steps to create an Ubuntu Live USB in a way that even beginners can follow without confusion.
We will focus primarily on Windows + Rufus, which is the most commonly used combination, while also briefly covering macOS and Linux.

4.1 Obtaining the ISO Image

First, prepare the ISO image that contains Ubuntu itself. This file includes the entire operating system required to boot Ubuntu.

● Download from the Official Ubuntu Website

Select the latest stable LTS (Long Term Support) version.
For most users, versions such as “Ubuntu 24.04 LTS” are recommended because they receive long-term updates and security support.

● You Can Also Choose Ubuntu Japanese Remix

The Remix version published by the Ubuntu Japanese Team includes:

• Japanese input support (Mozc)
• Japanese fonts
• Preconfigured Japanese locale settings

Because these are already set up, it is especially beginner-friendly for Japanese users.

Either version works perfectly for creating a Live USB.

4.2 Creating the Live USB Using USB Writing Software (Windows + Rufus)

For Windows users, Rufus is highly recommended. It is easy to use and has a very low failure rate.

Step 1: Insert the USB Flash Drive into Your PC

Connect the USB flash drive and confirm that Windows recognizes it.
Be aware that all data on this USB drive will be erased.

Step 2: Launch Rufus

Download Rufus from its official website and run it.
Rufus does not require installation and can be used immediately.

Step 3: Configure the Required Settings

Set the following options in the Rufus window:

• Device: Select the USB flash drive you want to use
• Boot selection: Choose the downloaded Ubuntu ISO
• Partition scheme:
  • UEFI systems → GPT
  • Legacy BIOS systems → MBR
    (If unsure, GPT + UEFI is generally recommended)
• File system: FAT32
• Volume label (optional): For example, UbuntuLiveUSB

If you want to use persistence, you can specify the storage size using the slider described later.

Step 4: Start Writing

Once all settings are complete, click “Start.”
The USB flash drive will be formatted and the Ubuntu Live USB will be created.

Note: This process may take approximately 10–15 minutes.

Step 5: Boot from the USB and Verify Operation

After writing is complete, restart your PC and select the USB flash drive from the Boot Menu.

Example boot menu shortcut keys by manufacturer:

• Dell: F12
• HP: F9
• Lenovo: F12
• ASUS: F8
• NEC: F7
  (The key is usually displayed during startup)

If USB booting is successful, the Ubuntu boot menu will appear.

4.3 Verifying Operation After Boot (Try Ubuntu Mode)

When booting from the USB, you will see the following options:

• Try Ubuntu (Try without installing)
• Install Ubuntu

Select Try Ubuntu.

The Ubuntu desktop will then launch, allowing you to freely test applications, check settings, and connect to networks.

Checking Japanese Display and Input

In the standard Ubuntu version, Japanese input may require additional setup.
If Japanese input does not work:

• Settings → Region & Language → Add Japanese
• Enable the IME (Mozc)

This will resolve the issue in most cases.

4.4 Quick Guide for Creating Live USB on macOS and Linux

● macOS (Using balenaEtcher)

1. Install balenaEtcher
2. Select the Ubuntu ISO image
3. Select the USB flash drive
4. Click the “Flash” button to start writing

The interface is extremely simple, and there are very few points where users can get confused.

● Linux (Using Built-in Tools)

On Ubuntu-based systems, you can create a Live USB using tools such as
Startup Disk Creator or the dd command.

Example: Writing the image using a command (for advanced users)

sudo dd if=ubuntu.iso of=/dev/sdX bs=4M status=progress

5. Advanced Usage: Persistence Setup and Practical Use

By default, Ubuntu Live USB has a key limitation: all settings and files are lost after reboot.
However, by enabling persistence, you can create a storage area on the USB drive that allows:

• Installed applications
• Wi-Fi settings
• Wallpaper and theme changes
• Work files and documents

to be retained across reboots.

This section explains how persistence works, how to set it up, and its real-world advantages and limitations.

What Is Persistence?

● A Mechanism to Save Settings and Data on the USB Drive

A standard Ubuntu Live environment is designed primarily for trial use.
When the system is rebooted, it returns to its initial state.

Persistence works by reserving a dedicated storage area (such as casper-rw) on the USB drive
and recording changes there.

This allows a Live USB environment to retain:

• Japanese input settings
• Browser bookmarks
• Installed applications
• Terminal command history
• Wi-Fi connection information

As a result, the Live USB can function as a truly portable, personal Ubuntu environment.

● Use Cases Where Persistence Is Especially Useful

• When you want a portable Linux environment with saved personal settings
• When you need the same environment on different PCs at work or while traveling
• When you want to use a lightweight Ubuntu setup on low-spec hardware
• When you need to move test environments easily

How to Enable Persistence Using Rufus (Windows)

Rufus fully supports persistence, making the setup process very straightforward.

Step 1: Open the Standard Live USB Creation Screen

Select the USB flash drive and load the Ubuntu ISO image as usual.

Step 2: Adjust the “Persistence Storage” Slider

Rufus displays a slider labeled “Persistence storage.”

Use this slider to specify the size of the persistence area.

• 4 GB
• 8 GB
• 16 GB or more (depending on USB capacity)

Move the slider to the right according to how much persistent storage you want.

Step 3: Create the Live USB

Simply click “Start” as usual to complete the creation of a persistence-enabled Ubuntu Live USB.

What You Can Do with Persistence Enabled

● Saving System and User Settings

• Japanese input settings (Mozc)
• Clock and language settings
• Desktop themes and appearance

All of these settings remain intact even after rebooting.

● Installed Applications Are Also Preserved

• VLC
• Visual Studio Code
• Python packages
• Development tools such as Git

Because everything is stored on the USB drive, it can function as a portable development environment.

● Retaining Browser Data

• Bookmarks
• Extensions
• Login information (use at your own risk)

You can use Chrome or Firefox as your own personalized environment.

Disadvantages and Important Notes About Persistence

Persistence is extremely useful, but it also has limitations and risks that you should understand in advance.

● Performance Degrades with Slow USB Drives

If you use a USB 2.0 drive or a low-quality USB flash drive, application launches and system updates can become very slow.

USB 3.0 / 3.1 or newer is strongly recommended.

● Persistent Storage Is Vulnerable to Corruption

Because persistence involves frequent write operations, the persistent storage area (such as casper-rw) can become corrupted.

Corruption is more likely to occur in the following situations:

• Transferring a large number of files
• Running apt update / apt upgrade too frequently
• Forcibly removing the USB drive

If corruption occurs, the Live USB usually needs to be recreated.

● Stability Differs from a Full HDD/SSD Installation

A persistence-enabled Live USB still relies on a “temporary storage layer,” which means:

• Kernel updates
• Large system upgrades

are generally not recommended or expected to work reliably.

Recommended Use Cases for Persistence

● Portable Development Environment

You can bundle environments such as Python + VS Code + Git onto a USB drive and use the same setup on any PC.

● Temporary Work OS While Away from Home

You can use your own Ubuntu environment on work or school PCs without modifying their internal systems.

● Emergency Recovery OS with Saved Tools

Installing recovery and diagnostic tools in advance can be extremely helpful.

• Disk checking tools
• Partition management tools
• Network diagnostic utilities
• Data recovery tools

This allows you to create a reliable emergency USB that is ready when needed.

By using persistence effectively, Ubuntu Live USB evolves from a simple trial environment into a fully functional portable Ubuntu system.

6. Common Problems and How to Fix Them

Ubuntu Live USB is relatively simple, but issues can still occur during creation or booting.
Here, we summarize the most common problems reported by users, along with their causes and solutions.

6.1 The System Does Not Boot from the USB (Most Common Issue)

● Common Causes

• USB boot is disabled in BIOS/UEFI
• Boot priority is still set to the internal disk
• Secure Boot is enabled
• UEFI and Legacy modes do not match
• The USB drive was not created correctly

In particular, Secure Boot and boot order issues account for the majority of cases.

● Solutions

1. Enter BIOS/UEFI
   Press F2 / DEL / F12 immediately after powering on the PC.
2. Enable USB Boot
   • Boot Menu: USB Storage / Removable
   • Set Boot Priority so that USB is first
3. Disable Secure Boot Temporarily
   On some systems, Secure Boot prevents USB booting.
4. Review UEFI / Legacy Mode
   • Newer PCs → UEFI
   • Older PCs → Legacy (CSM)
5. Try a Different USB Port
   If booting fails on a USB 3.0 port, trying a USB 2.0 port may help.

6.2 The System Boots but Japanese Input Does Not Work

● Cause

In the standard Ubuntu Live environment,
Japanese input (IME) may not be configured by default.

● Solution

1. Open Settings → Region & Language
2. Add Japanese
3. Set the input method to “Mozc (Japanese)”
4. Log out and log back in

Note: Ubuntu Japanese Remix provides Japanese input support out of the box.

6.3 Cannot Connect to the Network or Wi-Fi Is Not Detected

● Common Causes

• Network drivers are not automatically detected
• The Wi-Fi chipset is not supported
• A hardware Wi-Fi switch is turned off (common on older laptops)

● Solutions

1. Connect via wired LAN and update once
   In many cases, the required drivers are installed automatically.
2. Open “Additional Drivers”
   Available Wi-Fi drivers may appear and can be enabled.
3. Check the hardware Wi-Fi switch
   Some older laptops have a physical switch.

6.4 Persistence Does Not Work (Settings or Files Are Not Saved)

● Causes

• Persistence storage was not configured when creating the USB
• The persistence area (casper-rw) is corrupted
• Insufficient available storage space
• The creation method does not support persistence

● Solutions

1. Recreate the Live USB with persistence enabled
2. Increase the size of the persistence storage
3. If corrupted, recreating the Live USB is the fastest fix

Persistence is powerful, but unlike a full installation,
it is not well suited for large updates or heavy write operations.

6.5 The USB Is Too Slow and the System Feels Sluggish

● Common Causes

• Using a USB 2.0 flash drive
• Low-quality USB products
• Performance degradation due to heavy usage over time

● Solutions

• Use a USB 3.0 or newer high-speed model
• Choose a product from a reliable manufacturer
• If possible, using an external SSD provides dramatically better performance

6.6 Ubuntu Live Mode Crashes or Freezes

● Causes

• Incompatibility with the PC’s graphics driver
• Mismatched boot options
• Insufficient memory (common on PCs with less than 4GB RAM)

● Solutions

1. Try “Safe graphics mode” from the boot menu
2. Use a lightweight variant such as Xubuntu or Lubuntu on older PCs
3. Try a different version (for example, an earlier LTS release)

Most Live USB issues are caused by PC-side configuration problems rather than the USB itself.
By checking settings one by one, most problems can be resolved.

7. Summary and Next Steps

In this article, we covered everything from the basics of Ubuntu Live USB to creation steps, advanced usage, and troubleshooting.
Here, we summarize the key points and suggest what to do next.

7.1 Overall Summary

● What Is Ubuntu Live USB?

It is a system that allows you to boot Ubuntu from a USB drive,
with the major advantages of no installation, no risk to existing data, and safe experimentation.

● Why Live USB Is So Popular

• Use Ubuntu while keeping your current OS intact
• Test or revive older PCs
• Excellent as an emergency recovery environment
• Carry a full OS on a single USB drive

It is one of the best ways to experience Linux for the first time.

● What You Need to Create One

• A USB flash drive (8GB minimum, 16GB recommended)
• An Ubuntu ISO image
• A writing tool such as Rufus or balenaEtcher
• A PC with USB boot enabled

With these items, anyone can create a Live USB easily.

● Persistence

By enabling persistence, the Live USB becomes a practical portable Ubuntu environment capable of saving settings and files.

7.2 Recommended Next Steps

Step 1: Learn Basic Ubuntu Operations

• How to open the terminal
• How to install applications
• Basic file operations

Step 2: Install the Applications You Need

Developers can install VS Code or Git, while general users may want Chromium or LibreOffice.

Step 3: Install Ubuntu for Daily Use

If Live USB works well, installing Ubuntu as a primary OS is a natural next step.

Replacing an HDD with an SSD can dramatically improve performance on older PCs.

Step 4: Build a Full Environment on an External SSD

USB flash drives have speed limitations, but installing Ubuntu on an external SSD provides:

• High performance
• Stability
• Portability

7.3 Final Thoughts

Ubuntu Live USB is an excellent solution for people who want to try Ubuntu, revive old PCs, or experiment safely without risk.

If this article lowers the barrier to entering the world of Linux even slightly, it has achieved its goal.

Next, we will move on to a FAQ section to answer common questions readers often have.
Please continue reading with confidence.