Component grouping and keypath selection

[SurajNair]

When I repackage an Off the shelf application (say office) the Set up editor tab (in Installation Expert) automatically groups files to components and assigns one of those files as Key paths for each component. How does the Windows Installer decide
a. The components collection
b. That a particular file is the Key path for a set of files?

 

[kiptek]

This is from Wise knowlegebase ==>
The Windows Installer enforces the following rules on components:

* No applications that share a component can require different versions of any of the resources (files, Registry keys, etc.) included in that component. This is another way of saying that components are invariant.

* All files in a component must be installed to a single folder. Files can't be installed to subfolders without being contained in separate components.

* A component can include at most one COM server. If a component includes a COM server, that file must be the key path for the component.

* A component can include at most one file that is the target for a Start Menu or Desktop Shortcut.

* No file can ever be included in more than one component. This rule applies not only across components in a single Installer database, but across products, version and even manufacturers. If you must include a file in a different component than the one in which it is already included, you must change the name of the file. The same rule applies to Registry entries, shortcuts, and other resources.

* If a component is not 100 percent backwards compatible with a pervious version, it must be assigned a new component code. If backwards compatibility hasn't been completely tested, you must assign a new component code.

* Because changing a component code amounts to defining a new component, when you change the component code, you must change the name of every file, Registry key, shortcut, and other resource in the component.

* Similarly, if you change the name of a file, you must change the component code for the component that contains that file, and then change the name of every other file and resource in that component.

* The version of a component is determined entirely by the version of the key path file. If the computer already contains a newer version of the key path file, the component will not be installed. The version of non-key path files in the component won't even be checked by the Installer.


===>
kip