Her computer was following a strict set of instructions called the . This is a priority list stored in a special chip on the motherboard (the BIOS/UEFI) that tells the computer: "First, check the USB port. If nothing is there, check the DVD drive. Finally, boot from the hard drive."

It was a quiet Tuesday when Maya’s Windows 10 desktop started acting up. A blue screen. Then another. Her files were backed up, but the operating system itself was corrupted. She needed to reinstall Windows from a USB flash drive.

She inserted the drive, restarted the computer... and Windows booted normally again, ignoring the USB stick entirely.

She learned that the boot order is like a bouncer at a club: it decides who gets in first. And with a few key taps at startup, you can change that bouncer's list anytime.