Not really sure what you're asking here? Are you saying that if you offer a .pdf as a download product you'd like to force the file to save rather than opening in Adobe Reader? You can't really do that without designing some sort of custom download management tool. Each browser handles these types of things differently, and IIS handles different MIME types differently so you won't be able to just force a download without creating your own download management tool that requires the customer to save the file.
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