A BUP file

Computer file

A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...

 (Back UP) is a backup of the IFO

IFO

IFO is a type of DVD-Video file that stores information about chapters, subtitles and audio tracks.An IFO file is one of three types of files that are used on DVDs. It contains important navigational information, such as where a video chapter begins, and where audio and subtitle streams exist...

file on a DVD, which contains the information about the organization of tracks, menus, chapters, subtitles on the disc. BUP files are used in the event that the corresponding IFO file is unreadable, perhaps due to a scratch

Scratch

Scratch may refer to:* A mark or indentation on a surface: Abrasion It may also refer to:- Recordings :* Scratch , by Kaela Kimura* Scratch , the soundtrack to the 2001 documentary Scratch...

 on the surface of the disc.

Other DVD files include VOB

VOB

A VOB file is a container format in DVD-Video media. VOB can contain video, audio, subtitle, menu and navigation contents multiplexed together into a stream form. VOB is based on the MPEG program stream format, but with additional limitations and specifications in the private streams...

 files.

BUP files may also be BIOS

BIOS

In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....

update files. Fujitsu use .BUP files which then need the DskFlash executable to install the new BIOS from windows.