go to www.3vix.com get somthing called the divx doctor well you relay need the divix valadator it works better and faster i think it comes with the divx doctor well at least it use to. then use quicktime. also if you go to www.edivx.com and dl divx 5.02 that will help but you need the divx valadator.
that is for .avi

for asf use win meda plaer you should not have a problem
for .rm or .ram use real player if you have os x user real one and away you go.

also go to the control pannel open quicktime settings then update qucktime that should help