Bootable USB

A bootable USB drive contains an operating system image or tool written in a way that the computer firmware (BIOS or UEFI) can start it. It is created by writing an ISO image to the drive with a tool such as Rufus, balenaEtcher or the dd command, not by copying the file normally.

Why it matters

It is the standard way to install Windows or Linux, run a live system without changing the disk, reset a forgotten local password or run diagnostics when the installed system will not start. The computer must be told to boot from USB, usually through a one-time boot menu key such as F12, F10 or Esc, which varies by manufacturer.

Example

On Linux, writing an ISO to a stick at /dev/sdb:

sudo dd if=ubuntu.iso of=/dev/sdb bs=4M status=progress conv=fsync

This erases everything on the stick. Choosing the wrong device, such as your system disk, would destroy data, so verify with lsblk first.

Common mistakes

• Dragging the ISO onto the drive as a normal file.
• Writing to the wrong disk.
• Forgetting Secure Boot or the boot mode (UEFI vs legacy) when the stick does not show up.

Related

• ISO file
• BIOS and UEFI
• Boot process
• Thumb drive

यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.