I noticed that you are on a PC so I am not sure this will work, but it won't cost anything. I have Divx files that I changed the "open with" to OuickTime and they work just fine (had a little trouble with Divx player after Leopard). On Macs you usually download flip4mac or Perian to get different files to work, don't know if you have to do that on PC using Quicktime. Any way try downloading a free copy of Quicktime and changing the open with of your Divx movie to Quicktime and see if that works. If that works you will just have to find out a way to change tons of them. If this doesn't help at least if keeps the thread going for you.