Right-clicking on the text and selecting "Remove" from the resulting menu works for me. The blue color, underlining and clickability all go away. I tried with a directory path, a URL, and the "file:" example. All were initially automatically turned in to links; all were successfully unlinked by right-clicking and selecting Remove. This is on Windows 7, Evernote 5.0.3.1614. I agree that the automatic behaviour should be optional. I dislike programs trying to guess my intentions. If I want a link, I'll make one.
