Windows installer forbid certain install locations

Question

Have an msi file that is run by the user manually. They need to be able to choose the install directory in most cases however we need to forbid certain install locations. E.g. Installing it to the root directory C:\ will cause all kinds of problems, so we need to either overwrite that decision (i.e. overwrite C:\ with C:\Program Files (x86)\xxx) or pop up with an error. Is there some way I can enforce this?

The msi in question has custom actions already however there doesn't seem to be a way to edit the install location from there.

Alternatively, the msi in this case is wrapped up in a WiX bundle so if we can forbid certain directories from there that would also be good. Cannot find a way to do this either though (only know how to edit the default with <Variable Name="InstallFolder" ...>)

Only other solution I can think of would be rather horrible: make a separate application that selects a directory that then runs the installer with acceptable directory.

Can this be done either through an msi or a WiX Bundle?

I am using the "Visual Studio 2013 Installer Projects" extension to build the msi.

Answer 1

As a contrary view:

In general this is a bad idea. In most cases the correct answer will be to install the application code to the appropriate Program Files folder (64-bit or x86) and the data files to data locations and so on, and the user should get no choice. It is not clear to me that a choice is a good idea when (for example) the Windows Certification rules say that your code must go to the Program Files location, so just do it right. Users simply care that the installed application works correctly, and if it fails when installed to some locations then the answer is to either 1) Fix the application so that it works or 2) use Program Files and give the user no choice.

Also, if you are using Visual Studio Installer projects then you can't write custom actions to do this because they all run too late to change the install location. You seem to have discovered this already. But you CAN hide the browse folder dialog and install to the default correct location.

The other issue is that it's not clear how you would define an "allowed" location. If it's not C:\, then can it be D:\SomeOtherLocation? Can it be an attached USB drive? Can it be a network share such as \\Servername\share? A mapped drive to a network share? There are likely to be any number of chosen locations that will fail the install or the app when it runs, and I don't think there can be a useful list of what's allowed. On top of that, let's say you have a 32-bit install and the user chooses the native Program Files folder on a 64-bit system, then it won't even go there - it will be redirected to the Program Files(x86) location. Finally, it's not clear what you do in silent install mode assuming the user specifies a location on the command line, it fails your test, then the install silently fails (because silent means silent, and the install might be unattended).

In other words, just install to Program Files and have done with it.

Answer 2

Based on the users being able to manually install it (and hence using the UI sequence), it might be easier to:

1. In the InstallUISequence, sequence the LaunchCondition action to just before the ExecuteAction action.

2. Then in the LaunchCondition table, add a condition like so:

   Condition: TARGETDIR~<<"C:\Program Files\"

   Description: You must install to the Program Files folder

What we're saying in the condition is:

If the TARGETDIR starts with "C:\Program Files\" (therefore the user can install anywhere under this folder) continue with the install. Otherwise throw an error.

Rather then preventing certain locations, I'd probably just enforce the Program Files folder as a best practise.

Answer 3

Custom Action: This will be short. Will check back later. I can't say I have bothered implementing this recently, but a custom action can certainly inspect the installation location and abort the setup or halt it - if the path selected is found to not be satisfactory. It should also be noted that MSI actively resists installing directly to the root of C:\ and stuff like that due to the way the Directory table is implemented.

GUI: I guess one way would be to run a custom action when the user clicks the Next button in the setup's destination path customization dialog which then does "whatever you want" in terms of checking the path, and then reports any errors. This involves a DoAction event hooked up to the OK or Next button on the path customization dialog.

Silent Mode:You can also hook up the same custom action to run in silent mode (or another custom action calling the same path check function) - to account for the fact that an undesirable path could also be specified for a silent installation. In that case the custom action should abort the setup after writing into the log file, instead of reporting the path problem to the user - which is what you would do from the dialog event mentioned above - obviously.

Github: I do not have WiX code for you to implement this available on this computer. I would hit github.com and search for other projects that use WiX - you will probably find something quickly - no money for nothing and WiX for free.