all changes in RAM until the user logs off. A write-locked SD card (known as a Live SD, the solid-state counterpart to a live CD) in a USB flash card reader adapter is an effective way to avoid any duty cycles on the flash medium from writes and circumvent this problem. The SD card as a WORM device has an essentially unlimited life. An OS such as Linux can then run from the live USB/SD card and use conventional media for writing, such as magnetic disks, to preserve system changes; . Setup Various applications exist to create live USBs; examples include Universal USB Installer, Rufus, Fedora Live USB Creator, and UNetbootin. There are also software applications available that can be used to create a Multiboot live USB; some examples include YUMI Multiboot Bootable USB Creator and Ventoy. 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 16 MiB (Tiny Core Linux) to a large DVD-sized install (4 gigabytes). To set up a live USB system for commodity PC hardware, the following steps must be taken: A USB flash drive needs to be connected to the system, and be detected by it One or more partitions may need to be created on the USB flash drive The "bootable" flag must be set on the primary partition on the USB flash drive An MBR must be written to the primary partition of the USB flash drive The partition must be formatted (most often in FAT32 format, but other file systems can be used too) A bootloader must be installed to the partition (most often using syslinux when installing a Linux system) A bootloader configuration file (if used) must be written The necessary files of the operating system and default applications must be copied to the USB flash drive Language and keyboard files (if used) must be written to the USB flash drive USB support in the BIOS’s boot menu (although there are ways to get around this; actual use of a CD or DVD can allow the user to choose if the medium can later be written to. Write Once Read Many discs allow certainty that the live system will be clean the next time