You have absolutely, 100% sure, deleted every shortcut to the launcher, right? There's really nothing besides a command-line parameter that can be causing this, that I can think of.

The steps Silvonis suggests will use different registry keys (because it uses a different Windows user), and will rule out any leftover installation elements, so that's the next step in narrowing down where the problem is. But the client never actually stores the file version -- it downloads it every time you start unless there are shortcut parameters, so I don't know of any reason how that would help. Then again I don't know how you're running into the problem, so I guess that's the next step!

Edit: actually before you go to that trouble, there may be a clue in the launcher's log file. After running the launcher, there will be a file called output_log.txt in the ProjectGorgonLauncherWin_Data directory. If you can find that file and email it to eric@projectgorgon.com I'll take a look. Thanks!