VERIFIED SOLUTION i

MailStream Plus 8.3.2 and later- Using MSDRWF (MSDRWF.exe) and getting error about not being able to find MSDR01.acu

Issue

From a DOS windows you might see errors similar to this before MailStream itself starts to run-

'C:\Program' is not recognized as an internal or external command,
operable program or batch file.

and/or in the <jobname>.err file in the data folder, you see errors like this-

Try loading 'MSDR01.acu'...
MSDR01.acu: The system cannot find the file specified.
Try loading 'MSDR01'...
MSDR01: The system cannot find the file specified.
Try loading 'C:\Program\MSDR01.acu'...
C:\Program\MSDR01.acu: The system cannot find the file specified.
Try loading 'C:\Program\MSDR01'...
C:\Program\MSDR01: The system cannot find the file specified.
Try loading 'Files\MSDR01.acu'...
Files\MSDR01.acu: The system cannot find the file specified.
Try loading 'Files\MSDR01'...
Files\MSDR01: The system cannot find the file specified.
Try loading '(x86)\Pitney\MSDR01.acu'...
(x86)\Pitney\MSDR01.acu: The system cannot find the file specified.
Try loading '(x86)\Pitney\MSDR01'...
(x86)\Pitney\MSDR01: The system cannot find the file specified.
Try loading 'Bowes\MSP832F1\lib\MSDR01.acu'...
Bowes\MSP832F1\lib\MSDR01.acu: The system cannot find the file specified.
Try loading 'Bowes\MSP832F1\lib\MSDR01'...
Bowes\MSP832F1\lib\MSDR01: The system cannot find the file specified.
Try loading 'C:\PROGRA~2\Group1\ML360240\lib\MSDR01.acu'...
C:\PROGRA~2\Group1\ML360240\lib\MSDR01.acu: The system cannot find the file specified.
Try loading 'C:\PROGRA~2\Group1\ML360240\lib\MSDR01'...
C:\PROGRA~2\Group1\ML360240\lib\MSDR01: The system cannot find the file specified.'

Cause

This may be due to the command having spaces in folder names.  For example, say the command being used looks like this:

 call C:\Program Files (x86)\Pitney Bowes\MSP832F1\lib\MSDRWF.exe -jIVP -iC:\Users\Public\Documents\Pitney Bowes\MSP832F1\data\mspinput.txt -pC:\Users\Public\Documents\Pitney Bowes\MSP832F1\data\ivp.prm
 
This is due to the way Windows parses command lines. The spaces are read as folder name delimiters.  

Resolution

UPDATED: April 21, 2017
There are various ways to get around this  (Google-ing about 'spaces in Windows folder names' can show several).  
One of the simplest is to add quote marks around the entire path including the file name wherever needed.  Like this-

call "C:\Program Files (x86)\Pitney Bowes\MSP832F1\lib\MSDRWF.exe" -jIVP -i"C:\Users\Public\Documents\Pitney Bowes\MSP832F1\data\mspinput.txt" -p"C:\Users\Public\Documents\Pitney Bowes\MSP832F1\data\ivp.prm"