Do you mean photoshop elements 7? You can't burn a video dvd in PSE, any version. Output your slideshow as a wmv file and use whatever burning software you have to finalize the video dvd. If you have a disc burner, you have some kind of software that will do this.
The only kind of video disc you can burn in PSE without also having Premiere Elements would be a video CD. PSE only burns data dvds, not video dvds.