If you got a 700MB file in 1 1/2 hours you did good...

If it's a movie, it's almost certain to be a Divx avi file. Go to [http://doctor.3ivx.com] and download Divx Doctor, and see how you get on. Just launch the Doctor and drag your movie file into the window. Don't bother making standalone movies or decompressing sound. The Doctor will create a .mov file which reads from the original avi. Best of luck