Win31FileSystem

HKLM\SYSTEM\CurrentControlSet\Control\FileSystem

Data type	Range	Default value
REG_DWORD	0\|1	0

Description

Determines whether or not the FAT file system uses long file names and extended timestamps. This entry is designed to make the files stored on FAT volumes use only those features of the FAT filesystem as used by Windows 3.1 and earlier. Changing this value does not change any files, but it does change how FAT displays and manages the files.

Value	Meaning
0	Long file names and extended timestamps are used. Windows 3.1 and MS-DOS systems will be able to read the files, but will not be able to update the timestamp information or use the long file names (file names would be truncated to filena~1).
1	Long file names and extended timestamps are not used. Only those features of the FAT file system which were available to Windows 3.1 and earlier will be used.

Activation method

You must restart the system before a change to this value takes effect.

Note Image Note

Any discrepancies caused by setting this entry to 0, using a file on a Windows 3.1 or earlier system, and then opening the file on a Windows 3.51 or later or Windows 95/98 system, can be resolved by running chkdsk.

Setting this value to 1 will maximize compatibility with Windows 3.1 and MS-DOS systems.