Just a blank file in the WD directory…assuming that WD still has the capability.
The way it worked is when WD detects the file it starts up a second version, using absolutely nothing from your original install…to include registry settings. The fact that yours failed to run means either this functionality has been removed from WD, or, WD did not detect the file.
I just searched old posts and now I see references to 2wd.txt as the file name…the part i quoted earlier was directly from Brian’s post so I figured it would be correct.