What is how to boot from usb?

To boot from a USB drive, you'll generally need to access your computer's BIOS or UEFI settings. This is typically done by pressing a specific key during the computer's startup sequence. Common keys include Del, F2, F12, Esc, or F10. The exact key varies depending on the manufacturer of your motherboard or computer. The startup screen often displays which key to press.

Once in the BIOS/UEFI settings, you need to locate the boot%20order or boot sequence settings. Here, you can prioritize the USB drive as the first boot device. Save the changes and exit the BIOS/UEFI setup. Your computer will then attempt to boot from the USB drive.

If the USB drive is not recognized, make sure that it is properly formatted and bootable. A bootable USB drive contains the necessary operating system or bootloader files. You might need to use a tool like Rufus (for Windows) or create a bootable disk using the terminal (for Linux) to make the USB drive bootable. Also ensure the USB drive is plugged directly into a USB port on your computer and not through a hub.

Some computers also offer a boot%20menu that allows you to select the boot device on a one-time basis without changing the boot order in the BIOS/UEFI. The key to access the boot menu is often different from the BIOS/UEFI setup key, but it is also typically displayed during startup. Choosing the USB drive from the boot menu will boot your computer from it just for that one boot cycle.