growing PATH prevents a DOS program from running

[Norman Swartz]

Subject: Continuously growing PATH prevents a DOS program from running

I am running Windows XP Professional SP3.

A technique that I have used for years to run a DOS program inside of
Windows XP, no longer works. Apparently the PATH keeps growing, and when
it exceeds a certain size (255 bytes probably), legacy DOS programs will no
longer load.

Example: The path now reads

PATH=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBEM;C:\Program
Files\ATI Technologies\ATI.ACE\Core-Static;c:\utils\;C:\Program Files
\Common Files\Adaptec Shared\System;C:\Program Files\QuickTime\QTSystem\;C:
\Program Files\Smart Projects\IsoBuster;C:\Program Files\Common Files\Ahead
\Lib\;C:\Program Files\Common Files\Ahead\Lib\

It has expanded from its start-up value as

PATH=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBEM;C:\Program
Files\ATI Technologies\ATI.ACE\Core-Static;c:\utils\;C:\Program Files
\Common Files\Adaptec Shared\System;C:\Program Files\QuickTime\QTSystem\;C:
\Program Files\Smart Projects\IsoBuster

It's a mystery to me why all the other items have been added to the start-
up path as the computer runs for a while.

Your help will be most welcome. Thanks.

 

[John Wunderlich]

Subject: Continuously growing PATH prevents a DOS program from
running

I am running Windows XP Professional SP3.

A technique that I have used for years to run a DOS program inside
of Windows XP, no longer works. Apparently the PATH keeps
growing, and when it exceeds a certain size (255 bytes probably),
legacy DOS programs will no longer load.

Example: The path now reads

PATH=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBEM;C:\Pro
gram Files\ATI
Technologies\ATI.ACE\Core-Static;c:\utils\;C:\Program Files
\Common Files\Adaptec Shared\System;C:\Program
Files\QuickTime\QTSystem\;C: \Program Files\Smart
Projects\IsoBuster;C:\Program Files\Common Files\Ahead
\Lib\;C:\Program Files\Common Files\Ahead\Lib\ >
It has expanded from its start-up value as

PATH=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBEM;C:\Pro
gram Files\ATI
Technologies\ATI.ACE\Core-Static;c:\utils\;C:\Program Files
\Common Files\Adaptec Shared\System;C:\Program
Files\QuickTime\QTSystem\;C: \Program Files\Smart
Projects\IsoBuster

It's a mystery to me why all the other items have been added to
the start- up path as the computer runs for a while.

Often when you install a new program, its installer can add directories
to the Path that this new program needs to operate properly. You can
reduce the size of the path by replacing longer directory names with
their 8.3 equivalent name. Use the "dir /x <directory>" command to
reveal the 8.3 name. For example, typing:
dir /x \P*
would show you the 8.3 name for the "\Program Files" directory.

Using 8.3 names, the directory that you have in your path:
"C:\Program Files\Common Files\Adaptec Shared\System"
could probably be replaced with:
"C:\Progra~1\Common~1\Adapte~1\System"
which would save 15 precious bytes.

Make sure you use the "dir /x" command to use the correct 8.3 names.

HTH,
John

 

[Twayne]

If I recall correctly, the path limitation is 160 bytes, which includes
spaces and punctuation. But, your path statements have a lot of problems
in them.

Best fix is to shorten the path to where your programs live.

Also, are you manually entering these paths? I see a lot of wasted
space in what you're showing. I expected to see things like %windir%
instead of C:\...windows, etc.; saves a LOT of characters. Same for
many other system paths.
Also I see things like C:\windows and then C:\windows\system32, for
instance. Only the latter is needed, since on the way to sytem32, ALL
intervening directories will be inspected, meaning the separate
c:\windows is unnecessary; it will be found due to the latter entry.

I would recommend some reading in Help on System Folders naming
conventions, things like that. Here's a link to get you started:
http://www.wilsonmar.com/1envvars.htm

Do not assume that is all-inclusive; there are lots of nuances etc. to
the environment.

Additionally, not all legacy DOS programs will run in XP. But I
assume you know that.

HTH,

Twayne

 

[Norman Swartz]

Dear John and Twane,

Many thanks for your help. It took two days of laborious probing, but I
finally think that I have identified the culprit, namely, Nero 7 OEM. I
have now un-installed that application and have deleted every key in the
registry that contains "Nero". The path seems now not to grow constantly.

I found an old copy of Nero 6 OEM and will install it in a day or two. A
local computer guru tells me that Nero 7 OEM has caused grief on many
computers on which he has installed it and he much prefers Nero 6 OEM.

Just thought you'd like to know.