Personally I do not like it when installers silently install stuff; I like to be informed if they install something additionally (and always want to know where they install it).
Of course it depends on what you mean by 'silently'. Do you mean the user does not get informed at all? Or do you mean that the user could still opt out of the installation, but that the actual installation is done silently?... And in the last case, you have two other possebilities: Do you mean 'silently' as in no user interaction, but the progress and places where stuff is being installed is visible and the user can follow the progress?. Or do you mean completely 'silent', as in 'hidden' and the user would not have any clue something else is being installed?....
This is a personal thing, but I think many others feel the same and want to be able to opt out and to be informed of the installation and its progress. So, maybe something to take into account when making an installer...
just my .3 cents...
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