How to Create a Bootable Ubuntu USB in Windows

A full transition from Windows to Linux may not be easy, that is why Ubuntu allows its users to test the live CD (or USB) first to see if they like it, then install it on their systems. This guide shows you how to create a bootable Ubuntu USB in Windows. Using this media, you can boot up Ubuntu on any computer, perform your tasks and leave the main OS unmodified.

To follow along with the guide, ensure:

1. Internet connection to download the required tools.
2. A USB Flash drive – at least 8GB (recommended).
3. You have downloaded the latest version of the Ubuntu ISO from the official Ubuntu download page.

Also read: 7 Ways to Speed up Ubuntu

Create Bootable Ubuntu USB with Rufus

The easiest method to create a bootable Ubuntu USB is to use Rufus. The ability to set persistence in Ubuntu USB drives is now supported in newer versions of Rufus.

1. Plug your USB drive into your Windows computer. Next, launch Rufus and click the “Select” button to select the Ubuntu ISO.

2. Set the size for your persistence file.

3. Configure the partition scheme.

4. Click “Start” to flash the ISO.

Once the flash process is completed, reboot the PC into your Ubuntu system.

Create Bootable Ubuntu USB with UNetbootin

Another method to create a bootable Ubuntu USB in Windows is to use UNetbootin.

1. Download the UNetbootin tool from its official page.

2. Launch the UNetbootin tool. You may have noticed you can select the “Distribution” option, choose the distro you want to install and UNetbootin will download the ISO file for you. For this guide, we will use the “Disk Image” option since we have already downloaded the Ubuntu ISO.

3. Select the “three-dotted” section and navigate to the location of the downloaded Ubuntu ISO.

Select the Ubuntu ISO and load it into UNetbootin.

4. Before flashing the ISO to the USB, set up persistence. To do this, adjust the option “Space used to preserve files across reboots.” Allocate the desired space in MB.

Note: if you are flashing older Ubuntu ISOs, this might not work and you may need to perform a manual configuration as shown in the steps below.

5. In the “Type” drop-down at the bottom, make sure “USB Drive” is selected, select the Drive directory of your USB drive next to it, then click “OK” to start the process. After several minutes, the process will be complete.

You now have a bootable, portable Ubuntu build.

Also read: Make Linux Live USB Easily with balenaEtcher

Add Persistence Manually to the Bootable USB

In some instances, UNetbootin may fail to add the persistence. To resolve this, you can manually configure this option.

1. Download the Casper-RW-Creator file from the official link.

2. Once downloaded, launch the file and select the USB drive.

3. Set the persistence file.

Note: if you are using the Ubuntu 20.04 image, the persistence file has been renamed to writeable. However, for older images, select the persistence file as casper.

4. Select the size to allocate the persistence file and click “Create.”

5. Once the process is complete, you should have the file writeable or casper in the root of the drive for persistence.

To point Ubuntu to the persistence file, edit the “grub.cfg” file in “/boot/grub/grub.cfg.”

Find the entry:

 menuentry "Ubuntu" {
     set gfxpayload=keep
     linux   /casper/vmlinuz  file=/cdrom/preseed/ubuntu.seed maybe-   ubiquity quiet splash ---
     initrd  /casper/initrd
 }

Edit the file and add the casper module. The above entry should be:

 menuentry "Ubuntu" {
     set gfxpayload=keep
     linux   /casper/vmlinuz  file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet  boot=casper quiet splash persistent  ---
     initrd  /casper/initrd
 }

Finally, save the file and reboot the computer into your Ubuntu session. During Boot, select the “Ubuntu” section to use the persistence file.

Wrapping Up

You now have a bootable Ubuntu USB drive that you can take with you anywhere. It’s a great option in the way of security, ensuring you don’t have to enter and leave your data on strangers’ or public computers. As an extra measure, though, remember to password-protect your Ubuntu drive.

If you want to start from scratch and get yourself a blank flash drive, we can guide you through the process of formatting a USB drive in Windows. We can also show you how you to format a drive in FAT32 specifically, which isn’t possible using the native formatting tool in Windows 10.

John Wachira

John is a technical writer at MTE, when is not busy writing tech tutorials, he is staring at the screen trying to debug code.