If you look in the Help file of the axim, it will tell you there, About Windows Media Player, that it can play files with .asf, .wma, .wmv, and .mp3.
By the instructions, it reads on the bottom of page 54:
http://www.powershot.com/powershot2/pdf/g2/G2-SSG.pdf
DO NOT double-click a movie file (.avi extension) in the windows Explorer to play it. That will start WMP, w/c may not support this file type.
It seems that this typ of .avi might have a special coding where only QuickTime player is the only program that can play it. You might want to ask Cannon's Tech support.