Live USB

A live USB is a USB flash drive or external hard disk drive containing a full operating system that can be booted. Although they are closely related to live CDs in that they can be used in embedded systems for system administration, data recovery, or test driving, live USBs can persistently save settings and install software packages on the USB device. Many operating systems including Mac OS 9, macOS, Windows XP Embedded and a large portion of Linux and BSD distributions can run from a USB flash drive, and Windows 8 Enterprise has a feature titled Windows To Go for a similar purpose.

Personal computers introduced USB booting in the early 2000s, with the Macintosh computers introducing the functionality in 1999 beginning with the Power Mac G4 with AGP graphics and the slot-loading iMac G3 models. Intel-based Macs carried this functionality over with booting macOS from USB. Specialized USB-based booting was proposed by IBM in 2004 with Reincarnating PCs with Portable SoulPads and Boot GNU/Linux from a FireWire device.

Live USBs share many of the benefits and limitations of live CDs, and also incorporate their own.

Various applications exist to create live USBs; examples include the WinToUSB (Windows focused), Win32DiskImager (Windows focused), YUMI – Multiboot USB Creator, WiNToBootic (Windows focused) or Fedora Live USB Creator and UNetbootin and MultiSystem LiveUSB MultiBoot, which works with a variety of distributions. A few Linux distributions and live CDs have ready-made scripts which perform the steps below automatically. In addition, on Knoppix and Ubuntu extra applications can be installed, and a persistent file system can be used to store changes. A base install ranges between as little as 40 MB to as much as 1 GB.

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Wikipedia