Windows NT Support For Long File Names Under CDFS File System

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Windows NT supports the ISO 9660 level-two naming convention for long file names on a CD-ROM CDFS file system.


You may want to use long file names when creating a Window NT CD-ROM CDFS file system on your CD-ROMs. Windows NT supports long file names as listed in the ISO 9660 level two standards.

When creating a CD-ROM to be used under Windows NT, the following standards must be followed:
  • All directories and file names must be less than 32 characters.
  • All directories and file names must be in capital letters.
  • The directory tree cannot exceed 8 levels from the root.
  • File extensions are not mandatory.
Joliet and ISO9660

Joliet is an extension of the ISO9660 standard, developed by Microsoft for Windows 95, to allow CDs to be recorded using long filenames. For files recorded to CD, Joliet allows you to use filenames up to 64 characters in length, including spaces. Joliet also records the associated DOS-standard name for each file so that the disc may be read on DOS systems or earlier version of Windows.

Versions of Windows NT up to 3.51 build 1057 do not read Joliet discs. Windows NT 4.0 can read Joliet discs by design.

For additional information, please see the following articles in the Microsoft Knowledge Base:
ARTICLE-ID: 123067
TITLE : CDFS Does Not Support Lowercase Filenames

TITLE : ISO 9660 Support for CD-ROM


Article ID: 142372 - Last Review: February 28, 2014 - Revision: 2.3
  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • Microsoft Windows NT Server 4.0 Standard Edition
kbnosurvey kbarchive KB142372

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