DOS 8.3 filenames are also known as Short File Names, often abbreviated as SFN. It was a file naming convention that was used with older versions of DOS operating system. The versions of Microsoft Windows® released prior to the Windows 95® and Windows NT® 3.51.

DOS 8.3 filenames had at most 8 characters, followed by a period at times and a filename extension of not more than 3 characters. This almost antique file naming system is still used in modern versions of Windows® operating systems in order to ensure compatibility of these versions with older, 16-bit Legacy programs. However, the file system used must be FAT (File Allocation Table). NTFS file system is not supported by DOS 8.3 file naming system.

If enabled, the DOS 8.3 file name system can adversely affect system performance in newer versions of Windows®. When you try to open folders using your Windows® Explorer, you will find that the folders take some time to open. In order to remedy that, you can disable the DOS 8.3 filename system completely, unless you have to work with Legacy applications on a regular basis.

In order to disable this filename system, open up command prompt through your Start menu. Then type the following command at the prompt:

fsutil behavior set disable8dot3 1

Hit enter after you enter the command and restart your PC. The performance of your file system should be improved to some extent now.

You should always use this setting if you do not have to use Legacy applications frequently. If you do need to use some Legacy application some time in future, don’t worry. Simply type the above command in the command prompt and replace the 1 at the end with 0. Restart your machine and you will be able to use Legacy applications once more.