You should be able to drag-and-drop a file onto the track windows in order to create a video track, however ACID Pro only seems to "see" AVI files and I haven't been able to find a video format that it can open.
I was smart, to not delete Sony Acid Pro 7, I generally use mp4s to extract vocals such as samples fx, or certian lines out of movies, Acid pro 7 open just fine, so I take my samples and save them as WAV files just fine, I also purchased Magix Vegas Pro 14 for my video creation, I can take mp4 into that and convert to .avi, Its kind of a pain, takes more time.but if theres a will there is a way