I have downloaded the M100 software codec and unzipped using Stuffit Expander. It creates a Media100CodecsInstall folder that contains a __MACOSX folder and a Media 100 Codecs Install file represented as a document icon (which I find strange). When I try to install it, I get an error - There is no default application sepcified to open document "Media 100 Codecs Install". I am running OS X 10.2.8. Any help? Thanks.
You either have a corrupted StuffIt archive or an old version of StuffIt. Download the newest version of Stuffit expander and re-download the codecs. You should get an installer application after unstuffing.