How to Create a Bootable Ubuntu USB Drive - and Rescue Files from a Dead PC

A bootable Ubuntu stick gets a dead PC back on screen, so you can copy your files off it before deciding what to do next.

What you need

• A working PC with a decent internet connection, because the download is several gigabytes.
• A USB stick of 8GB or more, with nothing on it you want to keep.
• Rufus, which runs from the file you download and needs no installation.
• About fifteen minutes, most of it waiting.

Step 1: download Ubuntu

Go to Ubuntu's desktop download page and take the current LTS release.

LTS means long-term support, and it is the one to pick unless you have a specific reason not to.

The file is an ISO and it runs to several gigabytes, so start it downloading before you do anything else.

If you are not sure Ubuntu is the right distribution, the guide to Linux distros for beginners compares the ones that suit a first attempt.

Step 2: write the stick with Rufus

Open Rufus and plug in the stick, then set the four things that matter.

1. Device. Pick your USB stick, and check twice that it is the right one.
2. Boot selection. Click SELECT and choose the Ubuntu ISO you just downloaded.
3. Partition scheme. Leave it on GPT, which suits anything made in the last decade or so - MBR is for genuinely old machines.
4. File system. Leave whatever Rufus filled in - it reads the image and picks correctly.
5. Click START. If it asks how to write the image, choose 'Write in ISO Image mode'.
6. Confirm the erase warning and wait. Five to ten minutes on a USB 3 stick.

If Rufus says 'Unable to assign a drive letter'

This is a Windows problem rather than anything to do with your stick or the ISO. Windows has not handed Rufus a free drive letter, so the write never starts.

Three things clear it, in order of how often they work: unplug the stick and plug it back in, close any Explorer window or program still sitting on the drive, then disconnect a mapped network drive or a card reader if you have letters tied up.

You do not need to empty or format the stick first. Rufus erases it either way, and files already on it are not the cause.

Step 3: boot the broken PC from it

Plug the stick into the machine you want to rescue and switch it on, tapping the boot menu key as the logo appears. It is Esc or F9 on HP, F12 on most Dell, Lenovo and Toshiba machines, F12 or F2 on Acer, Esc or F8 on ASUS, F11 on MSI, and the Option key on a Mac.

Choose the USB drive from the list, then pick Try Ubuntu rather than Install. That loads a full desktop from the stick and leaves the hard disk completely alone.

If the stick never appears, look in the BIOS for Secure Boot and turn it off, then try again.

Getting your files off

Open the Files application from the dock. Your Windows drive shows up in the sidebar, and clicking it mounts it so you can browse it like any other folder.

Plug in a second USB drive or an external disk and copy across whatever you need. Users, then your account name, then Desktop, Documents, Downloads and Pictures is where almost everything lives.

If Rufus is not the right tool

Ventoy is better if you keep several rescue images around. You copy ISO files onto the stick and it boots any of them, so Ubuntu can sit beside a Windows installer without reformatting - the multi-boot Ventoy guide covers the setup.

balenaEtcher is the one to use on a Mac or a Linux machine, where Rufus will not run, and it verifies what it wrote afterwards.

Keeping Ubuntu after the rescue

If the live session convinced you, an older machine can run Ubuntu properly alongside Windows rather than instead of it. The dual-boot guide walks through sharing one drive between the two.

Quick questions

A stick you make in fifteen minutes is the difference between a dead PC and an afternoon of copying files off it. Download Rufus and build one before you need it, or tell us how the rescue went if you have already been there.