James,
I’m sure you must have already, but please verify that you read this: http://www.myeclipseide.com/PNphpBB2+file-viewtopic-t-5755.html
If you still can’t see anything, close MyEclipse, just download the MyEclipse 3.8.4 installer, run it, install it to a new location OTHER than your old MyEclipse location (e.g. C:\MyEclipse-3.8.4), start MyEclipse, go to Help > Software updates > Manage Config, right click on the existing MyEclipse extension, Disable it say NO to restarting, right click again, Add > New Extension, point to your MyEclipse dir, say NO to restarting. Close down MyEclipse. Edit your shortcut you use to launch MYEclipse, add -clean command line argument to the command, fire MyEclipse back up, verify ME is working. Now shut down MyEclipse, you are save to remove the old dir.
NOTE: I even think that running the installer and installing it ontop of your existing MyEclipse, letting it overwrite everything and relaunching with -clean will work, although this is not supported (because if it doesn’t work, we’ll just ask you to do a clean reinstall anyway).