Assuming you are in Windows OS environment. In windows explorer, right click on a CR2 file, click on properties, look at the Opens With item. Mine said Opens With Photos. I changed it to Poser executable. Done. All my icons are now looking like the good old red and white Poser ones. Do this for all your library file types - PP2, MC5 or MC6, CM2, HD2, and so on. You only need to process one file of each type.

Eternal Hobbyist