Browse your own registry, find the key .pz3 under HKEY_CLASSES_ROOT. It's "Default" data points to some other key. That is the key you need to use to identify which program will open up when clicking on a pz3 file. Find it (probably called poserFile or something like that) It should have a few sub-keys Shell->Open->Command . Command has, as it's default value, the fully qualified program and any default arguments that are called. As stated above, there are those who have multiple installations. This solution only finds that one that opens up when you double click a 'Poser File'. One additional word of concern. Thanks to user levels (something I actually agree with windows 2000 & XP), you might not have permission to do much with these keys (though you should be able to read them....I would hope). Visual C++ should enable you to get there, but I have never stepped outside of a programs own allocated registry space in VB, so I can't guarantee anything for VB.) Does this make any sense? (I tend to ramble :) eric