Editing USB flash drive (section)

===Booting operating systems===
<!-- This image is of a drive not supported by Microsoft any longer, so it should be replaced by something supported
[[File:Windows To Go USB Drive.png|thumb|Bootable [[Windows To Go]] USB flash drive|link=Windows To Go]] -->
Most current PC firmware permits [[booting]] from a USB drive, allowing the launch of an operating system from a [[bootable]] flash drive. Such a configuration is known as a [[Live USB]].<ref>[http://www.pcworld.com/article/2152040/aomei-partition-assistant-review-windows-to-go-no-longer-just-for-enterprise-users.html  Boot Windows from a certified USB flash drive] {{Webarchive|url=https://web.archive.org/web/20160225000757/http://www.pcworld.com/article/2152040/aomei-partition-assistant-review-windows-to-go-no-longer-just-for-enterprise-users.html |date=2016-02-25 }}. Retrieved on 14 May 2014</ref>

Original flash memory designs had very limited estimated lifetimes. The failure mechanism for flash memory cells is analogous to a [[Fatigue (material)|metal fatigue]] mode; the device fails by refusing to write new data to specific cells that have been subject to many read-write cycles over the device's lifetime. Premature failure of a "live USB" could be circumvented by using a flash drive with a write-lock switch as a [[Write Once Read Many|WORM device]], identical to a [[live CD]]. Originally, this potential failure mode limited the use of "live USB" system to special-purpose applications or temporary tasks, such as:

* Loading a minimal, hardened [[kernel (operating system)|kernel]] for embedded applications (e.g., network router, firewall).
* Bootstrapping an operating system install or [[disk cloning]] operation, often across a network.
* Maintenance tasks, such as virus scanning or low-level data repair, without the primary host operating system loaded.

{{As of|2011}}, newer flash memory designs have much higher estimated lifetimes. Several manufacturers are now offering warranties of 5 years or more. Such warranties should make the device more attractive for more applications. By reducing the probability of the device's premature failure, flash memory devices can now be considered for use where a magnetic disk would normally have been required. Flash drives have also experienced an exponential growth in their storage capacity over time (following the [[Moore's Law]] growth curve). As of 2013, single-packaged devices with capacities of 1&nbsp;[[Terabyte|TB]] are readily available,<ref name="tomshardware-1tb">{{cite web |author=Jane McEntegart |url=http://www.tomshardware.com/news/1TB-USB-Large-Capacity-Thumb-Drive-512GB-USB-DataTraveler-HyperX-Predator-USB-3,20278.html |title=Hands-on with Kingston's 1TB USB Stick |publisher=Tomshardware.com |date=2013-01-08 |access-date=2014-03-08 |archive-date=2014-03-08 |archive-url=https://web.archive.org/web/20140308063310/http://www.tomshardware.com/news/1TB-USB-Large-Capacity-Thumb-Drive-512GB-USB-DataTraveler-HyperX-Predator-USB-3,20278.html |url-status=live }}</ref> and devices with 16&nbsp;GB capacity are very economical. Storage capacities in this range have traditionally been considered to offer adequate space, because they allow enough space for both the operating system software and some free space for the user's data.