I know you aren't using a Macintosh; but for those who are---I started out making my slide shows (which also include video clips) using iMovie, because it came free on my computer. It not only allowed me to use transitions, but also to use transitions for the music so that I could have different music for different parts of the show. I also added a voice-over narration. I have since graduated to Final Cut Express, since it allows me even more power (special effects, keyframing, fancy titling, etc.). I make these shows of our trips and am constantly invited to places to show them to groups.