How can I configure special keys for IDM to prevent from taking a download or to force taking a download?
When you click on a download link in browser you can hold special key to prevent IDM from taking this download or to force taking it. To configure these keys you need to open "Options→General" IDM dialog and press "Keys".
Then enable "Use the following key(s) to prevent downloading with IDM for any links:" and "Use the following key(s) to force downloading with IDM for any links:" options and select keys or combinations of keys that you want to use. For most browsers it is better to use "Alt" key to prevent downloading and "Ins" key to force downloading.