Download the Ubuntu ISO image: Go to the Ubuntu website (https://ubuntu.com/download/desktop) and download the latest version of Ubuntu Desktop.
Create a bootable USB drive: Use a tool such as Rufus (https://rufus.ie/) or UNetbootin (https://unetbootin.github.io/) to create a bootable USB drive from the ISO image. The instructions to use these tools should be available on their respective websites.
Boot from the USB drive: Insert the USB drive into your computer and restart it. Press the appropriate key to enter the BIOS or UEFI settings, and change the boot order to boot from the USB drive. The key to enter BIOS/UEFI settings is usually F2, F10, F11 or Del.
Start the installation process: Follow the on-screen instructions to begin the installation process. You will be prompted to select your language, keyboard layout, and time zone.
Allocate disk space: Choose to install Ubuntu alongside your existing operating system or erase the entire disk and install Ubuntu. You can use pictures or screenshots from the Ubuntu documentation website (https://ubuntu.com/tutorials/install-ubuntu-desktop#1-overview) to help guide you through this process.
Create a user account: Enter your name, username, password, and other details to create a new user account.
Wait for the installation to complete: The installation process may take some time, depending on your computer's specifications.
Restart your computer: Once the installation is complete, remove the USB drive and restart your computer.
Log in to your new Ubuntu installation: Use the username and password you created during the installation process to log in to your new Ubuntu installation.
It's important to note that this is a high-level overview of the installation process, and that you should follow the instructions provided by Ubuntu as they may change depending on the version of the OS and the specific hardware of your machine. Additionally, it's recommended to backup your important data before proceeding with the installation and make sure your machine meets the minimum system requirements.