XPe and Merge Module

[Rich Noonan]

We are installing a 3rd party app which has "a core redistributable
Merge Module (.msm)
from Microsoft to ensure that core files are up to date." (quote from
3rd party)

This module is clobbering system DLLs with old versions and the 3rd
party is saying it's a problem with XPe. They state that on XP Pro
SP2 this module does not run and clobber, but that it fails to detect
XPe SP2.

I could install, un-clobber, reseal as part of my image build process,
but such acrobatics will be a problem with in-field upgrades of this
app. Can anyone suggest a workaround? Maybe a reg key I could add
that would prevent this merge module from running?

Thanks-
Rich

 

[Andy Allred [MS]]

Hi Rich,
This sounds like the classic scenario where the package was created to
redistribute a particular version of some system files like comctl32,
msvcrt, etc... If that's the case, then this should help explain why and how
to beat it:

The reason it appears to not happen on Pro is because system file protection
prevents those files from being overwritten. XPe however has file protection
turned off to provide you with more control over the system but it can be
protected by the more developer friendly features called Enhanced Write
Filter and File Based Write Filter.

If the msm is componentized as opposed to simply installing the app from the
desktop, then the developer could ignore these system files in the msm. If
you insist on running the installer though all you have to do is identify
the system files you don't want and *recopy* the original system files as a
post-install action of the msm.

Andy

 

[Rich Noonan]

The reason it appears to not happen on Pro is because system file protection
prevents those files from being overwritten. XPe however has file protection
turned off to provide you with more control over the system but it can be
protected by the more developer friendly features called Enhanced Write
Filter and File Based Write Filter.

Thanks for the reminder on write filters, Andy. I haven't implemented
either of these features yet, so I had completely forgotten about this
capability.

Unfortunately, due to the nature of the app being installed, vendor
relationship and app dependencies, I do need a solution that will
permit their installer to still be used from the desktop. There's
only 6 DLLs in question, so a file based write filter should be a
reasonable solution to implement and support.

Thanks-
Rich