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Q97595: MS-DOS 6.0 and 6.2: PATH Not Limited to 128 Characters

Article: Q97595
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:6.0,6.2,6.21,6.22
Operating System(s): 
Keyword(s): kbdisplay kbenv msdos
Last Modified: 10-JUL-1999

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The information in this article applies to:

- Microsoft MS-DOS operating system versions 6.0, 6.2, 6.21, 6.22 
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SUMMARY
=======

In MS-DOS 6.0, 6.2, and 7.0 (included in Windows 95) the 128-character
limitation of the MS-DOS PATH environment variable does not exist. To create a
path with more than 128 characters, use the PATH command in the CONFIG.SYS file
instead of in the AUTOEXEC.BAT file.

NOTE: When setting the path in the CONFIG.SYS file, you must use a SET command.
For example:

  set path=c:\dos;c:\windows;

MORE INFORMATION
================

There are some restrictions on this method of using PATH. Once you set the path
in the CONFIG.SYS file, you cannot change it later. You cannot use the %PATH%
variable to append the path onto itself or run another batch file to modify the
path. If you do either of these, the path is truncated to the first 128
characters.

Also, some applications do not have the ability to use a long path. For example,
the MS-DOS command SET does not display more than the first 128 characters of
the path. To see the complete path, use the OS option of Microsoft Diagnostics
(MSD.EXE). If you have problems using a third-party application and a long path,
contact the manufacturer of the application for possible solutions.


Paths Longer Than 256 Characters
--------------------------------

There is one problem with paths longer than 256 characters. If you clear the PATH
variable with the SET command as follows

  set path=

any characters beyond the 256-limit appear in your environment space,
unassociated with any environment variables. For example, if you have a path of
260 characters, such as

  path=c:\dos;c:\...work

and you clear it with the SET command, your environment space still contains the
last four characters. If you type the SET command alone to view your
environment, you see something similar to the following:

  work
  PROMPT=$P$G
  COMSPEC=C:\DOS\COMMAND.COM
  TEMP=C:\TEMP

Microsoft has confirmed this to be a problem in MS-DOS versions 6.0, 6.2, and
6.21. We are researching this problem and will post new information here in the
Microsoft Knowledge Base as it becomes available.

If the Path Is in the CONFIG.SYS File
-------------------------------------

If you place the path statement in the CONFIG.SYS file, you may need to manually
update the path whenever you install a new program. Many software packages use a
setup utility to install the program to the hard disk drive. Generally, these
setup utilities modify the AUTOEXEC.BAT file by adding a directory name to the
path statement. If the path statement is located in the CONFIG.SYS file, the
setup utility cannot find it and creates a new path statement in the
AUTOEXEC.BAT file. When the system is started, the path in the AUTOEXEC.BAT file
replaces the path loading from the CONFIG.SYS file, leaving you with a path
pointing to only one directory.

To work around this problem, each time you install a program, you must add the
program's directory name to the path in the CONFIG.SYS file and erase the path
line in the AUTOEXEC.BAT file.

Additional query words: maximum length w_bob win9x win95 win98

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Keywords          : kbdisplay kbenv msdos 
Technology        : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600
Version           : MS-DOS:6.0,6.2,6.21,6.22

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