Knowledgebase

20110406-2 -  Understanding the NtfsDisable8dot3NameCreation Security Setting
April 06, 2011

Most Microsoft Windows systems define an 8.3-compatible version of every single file:

• The "C:\Program Files" folder has "C:\PROGRA~1" as an alternative name
• The file "C:\Windows\WindowsUpdate.log" can be referred to as "C:\WINDOWS\WINDOWS~1.LOG"
• The alternative names use some of the characters from the original longer file name, but the relationship is not entirely predictable. For instance, on 64-bit systems, "C:\PROGRA~2" is often a shortcut for "C:\Program Files (x86)", but it may depend upon whether this folder or "C:\Program Files" was created first.

How this setting affects security and performance

For details, consult Microsoft's TechNet article on Additional Registry Entries, which is part of their Threats and Countermeasures guide.

The setting increases security on a system exposed to remote exploits, such as browser hacks. For instance, if an attacker found a way to delete files by name, they might have trouble guessing to delete "Policies and Procedures May 2012.doc" and "Mission Criticial Inventory.DB", while they might get lucky and delete them by their 8dot3 names "POLICI~1.DOC" and "MISSIO~1.DB"

The setting improves performance on folders with thousands of files. Listing a folder can take longer if every file has two valid names. Also, each time you create a new file in a large folder, more time is required to generate a unique 8dot3 version of the file name.

How this setting affects ERDAS Desktop Products

Most ERDAS Products are unaffected by this setting. However, certain legacy third-party modules rely upon the 8dot3 shortcuts to handle file and folder names that contain spaces. Since the default installation target ("ERDAS Desktop 2011") has multiple spaces, this setting can definitely affect the installation and operation for ERDAS IMAGINE, LPS, and ER Mapper.

If this setting is present in your group policies, or required on your individual computer system, it is still possible to use ERDAS Desktop Products. Consult the "Resolution Strategies" presented under Installation Problems with Error 193 or 8dot3.

ERDAS IMAGINE LPS