a short quote from the "Windows 7 Software Logo Requirements":
Technical Requirements
1) Clean, reversible, installation
A clean, reversible, installation allows users to successfully manage (deploy and remove) applications on their systems.
Applications must properly implement a clean, reversible, installation. The application should be able to roll back the install at failure and restore the machine to its previous state.
If I now haven an application as a prerequisite of just one feature and the installer crashes at the end of the main installation, the rollback will only affect the main installer and the prerequisite itself will stay on the system, as it got correctly installed.
But the machine does not have its "previous state" as the prerequisite changed the machine.
So how is it possible to pass the win7 logo requirements if we use this feature?
My interpretation of this requirement yields the following guideline: Ensure that each prerequisite either has an ARP entry (and can thus be considered separately from your main package) or is automatically uninstalled as part of rollback or uninstall of your main package. We offer nothing special for automating the latter, so we implicitly suggest the former.
The real trick is figuring out what "previous state" means, and when (which state) it means. Prerequisites don't tell you whether they install or were already present. Since many prerequisites represent shared dependencies that may or may not already be present on a target machine; blindly uninstalling one when another application may have installed and rely on it is much worse than leaving behind a shared dependency with its own ARP entry. I thus find a "previous state" right before the failing installation's execute sequence was started, not necessarily the one before they clicked on your setup.exe, to be more useful.
Those prerequisites are actually real applications, with complete ARP entries and fully functional, even if the main installation fails.
I thus find a "previous state" right before the failing installation's execute sequence was started, not necessarily the one before they clicked on your setup.exe, to be more useful.
We, of course, agree with you, the question is: Will Microsoft agree? 🙂
Yes, that is the question. I don't have an answer. I think, for instance, that Visual Studio installs several packages separately under a unified front end. If a later one fails (e.g. the actual IDE), I don't think its externally uninstallable dependencies (e.g. the corresponding .NET framework) are uninstalled. However I don't remember if Visual Studio acquires logo certification.
