Bootable media
In reference to computers, bootable media is any kind of storage device which contains a CMOS/UEFI usable operating system.[1] Although every computer has an operating system on its internal drive, there is sometimes a need for an independent system. Bootable media can involve Compact Disks (CD-ROMs), Digital Versatile Discs (DVDs), USB flash drives, external hard disk or solid-state drives, Compact Flash (CF) or Secure Digital (SD) cards, or other removable storage.
Uses
Removable bootable media is probably most often used when the local system has a problem, or information has been lost on the same internal drive. Bootable media enables the user or technician to easily access work on the computer without using the internal system, and in so doing, potentially making the problem worse. Of course, if the internal system is not functioning, bootable media is also often needed. Once a computer is running a system from external media, a variety of things can be done, including:
- Data recovery
- Bit/sector repair
- System restoration from a backup
- Complete system backup
- File manipulation (sometimes prevented by the local system)
- Malware search and removal
- Other system maintenance
In some cases, bootable media is used for other purposes as well. One purpose which is popular among certain circles is the use for anonymity. Rather than using the host system which will track activity, some use a bootable disk with a system such as TAILS to work on. When they are done, there is little record of what has been done left on the computer.
Portable operating systems
There are a variety of systems which may be installed on bootable media. Here are some common systems:
- Ultimate Boot CD for Windows (UBCD4Win)
- Hiren’s BootCD
- Ultimate Boot CD (or UBCD, not to be confused with UBCD4Win)
- The Amnesic Incognito Live System (TAILS)
Also, many GNU/Linux distributions offer an option to run the system from the install disk, rather than installing. There are also a variety of limited purpose systems offered by anti-malware companies such as Avast, Avira, and AVG which are designed for the sole purpose of scanning an infected computer for malware and removing it.
Some people instead opt to make bootable media from their own Windows operating system. Using a software package available on the World Wide Web and a specific set of files from their system, they can make removable media (usually a USB flash drive) bootable. However, this activity does not seem to comply with Microsoft's license agreement, so this process is not described here.
