Hi Beth, I'm running both v4 and v5 of PSE and did find the DigiMarc directory in the program files/adobe/photoshop elements.../Plug-Ins dir. What version are you running?
Debbie, putting the ~ in the directory name just means that plug in will not get loaded. Sounds like it's an unnecessary plug in to many people. So if you find that you are trying to do something and can't then perhaps remove the ~ in the directory name.
I try to take one day at a time, but sometimes several days attack me at once.