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Boot Disk

What Does Boot Disk Mean?

A boot disk is a removable data storage medium used to load and boot an operating system or utility program. Typically, a boot disc is a read-only medium that stores temporary files on a CD-ROM or floppy disc drive. Other boot disk mediums include USB drives, zip drives, and paper tape drives.


One of the most common uses of a boot disk is to start the computer when the operating on the internal hard drive does not load. Generally, a boot disk contains a full-scale operating system, and may include a small utility operating system as well. In recent years, boot disks have become less common as original equipment manufacturers turn to using hard drive partitions to store recovery data.

A boot disk may also be referred to as a bootable diskette, startup disk, bootable disk or bootable rescue disk.

Techopedia Explains Boot Disk

The boot disk is generally used to repair damage by restoring system files to a last effort or reinstalling the operating system to its original factory condition.

The boot disk is used for a variety of functions, including:

  • Customizing an operating system environment
  • Anti-virus and anti-spyware scans
  • Installing a full-scale operating system
  • Software and hardware troubleshooting
  • Accessing the operating system when passwords are lost
  • Data purging to remove old and unneeded data
  • Data recovery to restore damaged, corrupted or inaccessible data

In order for a boot disk to operate, a computer needs to have a built-in program to load and execute the instructions. All boot disks need to be compatible with the personal computers they are intended for. Some computers have a basic input/output system (BIOS) that supports booting from a device such as a CD-ROM or USB. Other systems may require a boot floppy to run software on a CD-ROM and do not support booting from just a CD-ROM.

If recovery data is not stored on a PC’s hard drive, an operating system generally provides the tools to create a boot disk.


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