About the MuPAD online help patch hlp_patch_142_1.zip :

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This patch applies only to MuPAD Pro 1.4.2 - Deutsche Version.  
You need this patch only if you have copied MuPAD Pro 1.4.2 - Deutsche 
Version before 24 Nov 1999.  If you have copied MuPAD later this patch
is not needed!
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1.  Installing the Patch:
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Copy the file hlp_patch_142_1.zip into the folder where the MuPAD 
executables are located. In the following it is assumed that MuPAD has
been installed under C:\Program Files\SciFace\MuPAD Pro 1.4.2 Then 
the executables are located in

	C:\Program Files\SciFace\MuPAD Pro 1.4.2\bin

In this folder extract the zip file. Simply overwrite the file mantoc.cfg

That's all.