>>MSI is a complex database.
>
>Thanks for the information on the MSI format. I was not aware it was some sort of database. I expected it to be some specialized executable format. I now understand more why most common and cheap installer-building package do not support it.
>
>>Installshield is sold the 3th time or so. I have skipped 15years running an old version on a XP on a VM (since at this time update
>>as online only and they never handed me a missing version for reinstall....
>>If you don not need multi-lang support and scripiting, Express is not that bad - and even the one shipped with VFP
>>should still do. At least it is enough for a try.
>
>I expect that I'll make a try with alternatives solutions, possibly one that does not support the MSI format.
>
>Do you know whether EXE-based installers convey any significant drawbacks vs MSI-file-based ones? in terms of user-acceptance or "access rights" control?
>
>Daniel

The user does not care. User clicks anything.
Exe based vs msi.
A setup.exe is something the user expects, some odd.msi file not. Anyway. Installshield wraps the msi into an setup.exe file. This will be deflated, run its script logic to configure the msi and then run the msi.
The good thing on msi base installs is that it integrates into the modul count logic. That is, if more then on install package uses a file - for example an dll - the logic keeps the dll as long as at least one package is existing. (It may keep it, this is a setting) I see a lot of installers that run additional packages like this or that .nrz setup and the like. Those do only remove itself - not the additional packages. This is what I consider poor on stuff like InnoSetup.
The dll is distributed inside a msm file (a msi like database for modul distribution) that simply hooks into the msi, so over various install packages the dll, with version, is
to identify. Also the msi holds the update logic. There is a way to create patches out of msi - something I've never used.
This is the way it should be done on an windows system. Guess how many use it. It's additional work, isn't it? I've spend the time ages ago, so I can reuse my old knowledge. I have never used anything else then msi since VFP was shipped with the crippled version. I've looked over InnoSetup after the 2017 Frankfurt Conference and found that I run into trouble with the distributed files (I have a bunch of may own) , so I kept my old Installshield. :)

Installshield is basically a wrapper to assemble the msi file. It adds an own script language and wrap the more ugly msi visual interface and inflate all of it into an exe file.
By design it can do mostly anything to the system. setting up registry, inifiles, start folder, name it. Setting up services, environment, simply the whole stuff. I do not know what InnoSetup can do - I've stopped to fast.