This only works with icons that are already in the Dock, because that’s where we are going to drag them from. First thing to do is be careful: make the wrong move and you will drag icons OUT of the Dock rather than dragging COPIES to the Finder windows. Nothing to worry about, just follow directions, which amount to a single step! Here it is:
Step One: HOLD THE COMMAND KEY while dragging an icon from the Dock to the top of a Finder window (the Toolbar). Which one is the Command key? It’s the one that isn’t Control, and isn’t Option. It’s the one with either an Apple, or a clover thingy, or both on it. It might even say “Command” right on it! Whichever, it’s right next to the Space bar.
Click here to learn how the Command key got its symbol.
Anyhow, if you hold the Command key down, and then you click and drag an icon from the Dock to a Finder window’s Toolbar, you’ll end up with the same icon in both places. Neat. You’ll see a little green circle with a white “+” in it while you drag, if you’re doing it right. If you don’t see the little green circle with the white “+” in it you will tear the icon right out of the Dock, accompanied by a puff of smoke and a little “poof” noise. If you don’t see the little green circle with the white “+” in it just drag the icon back to the Dock.
Command Key (no it will not be outlined in blue on your keyboard):
Little green circle with a white “+” in it:
Puff of smoke (you don’t want this):