Bootable media contains software that allows a computer to boot from a removable device like a USB flash drive. When booting, the computer performs self-checks, loads the BIOS which finds the boot loader on the hard drive, and then loads the operating system along with hardware drivers and any startup programs. Bootable USB flash drives provide an easy way to install operating systems without discs by creating a portable boot device.

1. Bootable Media

2. Bootable Media
 containing software used to boot a computer
 is a removable digital data storage medium from which a computer can
load and run (boot) an operating system or utility program.[1] The
computer must have a built-in program which will load and execute a
program from a boot disk meeting certain standards.
 Example;
1. Floppy Disk
2. CD
3. DVD
4. USB Flash Drives

3. Boot
 Alternatively referred to as boot up or sometimes start up, booting is the
process of powering on a computer and getting into the operating system.
How to boot
If the computer is in working condition, it boots automatically after turning on the computer. If
problems exist that prevent the computer from booting, an error message is often shown

4. What happens when a computer is booting?
 During the boot process, the computer goes through multiple steps to ensure the computer
hardware works correctly and the necessary software can be loaded. When booting, the
computer performs the following tasks.
1. Pressing the power button on the computer starts up the power supply, which subsequently provides power to
the other hardware components inside the computer case.
2. A self diagnostic is performed, also known as a POST, to check if all hardware in the computer is working
properly.
3. The BIOS checks the hard drive for the boot loader, located in the first sector of the hard drive.
4. The boot loader looks for the operating system on the hard drive and begins loading the found operating
system (e.g., Linux, macOS, or Windows).
5. Hardware drivers are loaded, allowing the operating system to interact and utilize the hardware components
inside the computer case.
6. If configured in the operating system, a login screen is displayed, allowing the user to enter a username and
password to log in.
7. Any additional software programs configured to start with the operating system, known as startup programs,
are loaded. Common startup programs include antivirus software or printer management software.

5. When the computer is
booting, you may see a
boot screen like the
example picture below.

6. Why You Need a Bootable USB Flash Drive
 Installations from a USB flash drive have become one of the easiest ways to update
your computer with a new operating system. A USB installation is quick, extremely
portable, and has the bonus of reverting to a storage device following the install.

7. Tools use to create a bootable flash
drive
1. Rufus 2. Windows USB/DVD Download Tool 3. YUMI