Hi,
I bought worms wmd but I'm french and I want to put the game to french. In game I don't find the option for langage change. The file alltextfra.bin is intalled but I don't know how to activate it.

Team 17 sucks, yet another case of it.
I've searched high and low and could find nothing certain.
Do you use galaxy? There might be a switch within galaxy that allows you.
The way steam people do it is within steam itself, not the game. Galaxy has similar functionality.

https://support.gog.com/hc/en-us/articles/360003935197-How-can-I-change-a-GOG-game-s-language-?product=gog

I'll keep looking around for a method for offline installer but I don't own the game, so kind of hard.

Hello,

If you used the offline installer, supposedly you can edit the shortcut to add language:french to the command line. Source.

If you use GOG Galaxy, click the "More" button to the right of the Play button and choose Manage Installation, then Configure. If available, you can select the language from the second dropdown menu near the top.