Disable creation of DOS compatible 8.3 filename

When a file is created a filename is attached to actual contents of the file. For the sake of compatibility, then a 8.3 filename is created along with the long filename. If running applications that creates many files, then they might show better performance if one disables the generation of the 8.3 filename.

To do this edit this DWORD registry key: (Only affects NTFS partitions)

[HKEY_LOCAL_MACHINE \System \CurrentControlSet \Control \FileSystem]

Note the utility fsutil can also be used to change this value:

fsutil behavior set disable8dot3 1

Note that original Windows 95 without SP1 will not be able to access files created.

Note that some applications still uses 8.3 filenames, and might fail to function (Ex. applications running at boot time ex. virus scanners or similar).

More Info MS KB121007
More Info MS KB130694
More Info MS KB142982
More Info MS KB183387
More Info MS KB210638
More Info MS KB226403


  1. Larry Miller says:

    Note the last sentence. All DOS and 16 bit Windows applications require 8.3 filenames. Some fairly recent 32 bit Windows apps require them as well. Be careful you are not using, or may use in the future, any such applications. Turning off short file name generation is easy, creating these names later if they are required can be a very difficult process.

    Larry Miller
    Microsoft MCSA

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