So let's say that I have a bookmark in my Firefox bookmarks sidebar with this as the 'Location': file:///E:/Name%20Of%20File.txt If I were to click that bookmark, the contents of that text file will appear in the browser which allows me to read the contents of the file. I want to be able to left-click that bookmark from the Firefox bookmarks sidebar or right-click it and select from a context menu and have that .txt file launch in a separate Notepad window, as in launching Notepad as an external application separate from Firefox. Is that possible with some tweaking and hacking or whatever?