It’s usually two separate setup files in my experience which I prefer. For example I don’t want a 64 bit version installed because my OS is 64 bit when the version I need of an app for example needs to talk to some 32 bit ODBC drivers. This is the situation I have with Navicat, although if have both 32 and 64 bit versions installed in this case but only the 32 bit version will talk to a legacy app. I prefer a choice.