Windows: Prevent accidental copies

Click the topmost file you want to copy. Hold down the Ctrl key and down-arrow through the list. You’ll see a faint selection rectangle that moves down as you press the arrow. When it reaches another file you want to copy, press the space bar. (If you select the wrong file, press the space bar again to deselect.) When you’ve made your selections, press C without releasing the Ctrl key to copy the files to the clipboard. Navigate to the destination folder and press Ctrl-V to paste in copies of those files.