4 replies to this topic

[Climber]

This seems the best place to ask this question as I would imagine that stripping out system files from installers and managing via merge modules is the best way to control file versions and eliminate potential conflicts in a large desktop environment. Is this true or are we just wasting our time trying to manage our desktop like this?

Exactly how effective is WFP at preventing conflicts between application using different versions of core system files?

Is the snapshot and repackage process of deploying software now redundant?

Any comment greatly appreciated

[Stefan Krueger]

WFP doesn't care about compatibility. It only makes sure that no system files are being overwritten by 3rd party installers, i.e. it prevents upgrades as well as downgrades. However OS service packs (including such things as Internet Explorer, MDAC etc) are able to upgrade these files, potentially causing problems.

The savest method to avoid DLL hell is application isolation, i.e. all the files are located in your own directory and loaded from there.

[Climber]

Thanks Stefan

I guess what I am trying to understand is best practice for re-wrapping of third party installers for a controlled environment.

If a third party installer delivers a newer version of a dll to the system32 folder and it is subsequently replaced by WFP for the original version, would a better design standard be to include any upgrades to system files in a separated merge module which was recognised by WFP as an ’official upgrade’. Then the risk of loss of functionality in an application could be reduced?


I have also experienced some problems even with isolated applications in that registry keys have been shared with core system files, so uninstalls have broken the base build.

[Stefan Krueger]

WFP protected files cannot be updated using MSI, also not in a merge module.
If a third party (non-Microsoft) setup tries to update a WFP protected file, I would call this a bug in the setup. All setups that install system files should carry appropriate conditions or perform checks, and not try to overwrite WFP files.

If you need to update such a file, run the setup or service pack from Microsoft. That's the only official and supported method. You can do this in your launcher or maybe in a custom action.

[Climber]

Thanks that partly addresses my query. I guess my next questions is what is the criteria for a file to be protected by WFP?

I assume if a file is not protected then the best way to manage version control if that file is used by multiple applications in a desktop environment is through a merge module?