If I remember correctly, the software installs in French by default (thanks for prompting me).
When I installed this software, I had to fumble my way through the menus until I found the language option. I don't speak French, but finding the right option wasn't too tough. The menus may not be in English, but they follow the "standard" layout. As long as you're not connected to the PLC, your chances of breaking anything are very slim. Take a quick look at the pull-down menus. Most menus go something like this: "FILE EDIT OPTIONS."
AK