How tell Dropbox to stay on my PC, but stay away from my Mac?

[Peyton T.]

I only want to use Dropbox on my PCs. I use my Mac only for testing the PDFs that I write on my PCs (to make sure they work properly for Mac users), and NOTHING ELSE. But when I try to download my PDFs to my Mac for testing, I find now that they go to Dropbox, and I can't get them onto my desktop (they don't drag, for example). But I never put Dropbox on my Mac. Apparently Dropbox put itself there automatically, or rather, put an interface there to wherever on the cloud it put my downloads. 

I do not want Dropbox - nor any interface to Dropbox - on my Mac. How can I take this interface off my Mac and tell Dropbox never to put it back?

[Rich]

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@Peyton T. wrote:

 But I never put Dropbox on my Mac. Apparently Dropbox put itself there automatically, or rather, put an interface there to wherever on the cloud it put my downloads.

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Dropbox can't install itself on your computer. The only way for Dropbox to be on your computer is if you (or someone) has installed it. And if you're downloading files from the Dropbox website (or anywhere, really), it's your browser that controls where they're saved.

How, exactly, are you downloading the files? Is the Dropbox application installed on the computer? Do you actually have a local Dropbox folder? If so, is your Downloads folder located in it?