As you may not know is that DE stands for Dell Edition and as such Dell has castrated that version of a 2 plus year old and three version behind software. You'll have to ask Dell what to do about it.
Was it pre-installed or did you have to install it? If you installed it, perhaps your anti-virus was on and not everything got put into your registry correctly. You may be able to fix it by uninstalling it and then reinstalling it
IF you have the disc or by using the Windows Add or Remove Programs repair function. Try using Revo Uninstaller in the Moderate mode if you want to start from scratch and have the disc.
In the mean time, if you go to the photo tab, you may see a Slide Show Assistant. You can use that to make a slide show and can be added to MyDVD 9 via add new movie.
Do you get back the ability to "edit movie" if you add a video file to MyDVD via "Add new Movie"?
Sometimes you get what you pay --- nothing for nothing !