Cannot Access 8.3 Filename from MS-DOS-Based Application

ID: q103072

The information in this article applies to:

SYMPTOMS

From an MS-DOS or 16-bit Windows-based application, you are unable to access a filename on a FAT or NTFS (over the network) partition that has 8 characters before the period and 3 after (8.3 file format).

CAUSE

You created an illegal (under MS-DOS) filename using the Copy command from Command Prompt. On FAT partitions, you can use spaces and other illegal characters. On NTFS partitions, if you use the 8.3 filename format, no MS-DOS-compatible filename is created, even if you use illegal characters.

All 32-bit Windows NT applications, such as Notepad and File Manager are able to access and manipulate these files because they have built-in long filename support. However, these files cannot be accessed by 16-bit MS-DOS or Windows-based applications either from Windows NT, MS-DOS, or Windows 3.1.

Steps to Reproduce Problem

1. Run Command Prompt from the Main group of Program Manager.

2. Type the following command: 

      copy con "bad name.txt"
3. Type some text and press ENTER.

4. Press F6 or CTRL+Z.

The resulting file will not be accessible from MS-DOS or 16-bit Windows-based applications.

RESOLUTION

The only workaround is to rename the file using legal characters for MS-DOS from File Manager or Command Prompt.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.1 and Windows NT Advanced Server version 3.1. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: lfn prodnt 

Keywords          : kbtool
Version           : 3.1
Platform          : WINDOWS

Last Reviewed: August 14, 1998