Une fonctionnalité ou amélioration spécifique offerte par Windows Copilot
Language note: Although the local post is fr-fr (French), your question is written in English so the answer is given in English for your convenience.
Hello Maxime MERCIER,
Thank you for sharing the detailed test results.
I was unable to find other reports that clearly match this specific behavior, and there does not appear to be an official announcement confirming a widespread issue at this time.
Microsoft’s current documentation also does not indicate that Copilot voice dictation uses the Windows display language to restrict which spoken languages it can recognize. Since French is officially supported, it should normally work without requiring Windows to be displayed in French.
Here are some suggestions you can try:
Open Copilot, select your profile picture, then check Settings > Preferences > Voice language. If available, choose French instead of Auto-detect. You can also open a voice conversation, select the gear icon, and set the language there.
If the issue continues in both the Copilot app and web version, please submit feedback through the Copilot app by selecting ... > Send feedback. You can also use the Microsoft Feedback Portal to vote for a similar report or create a new one.
Include the Windows display language, Copilot and browser versions, and the comparison results from your English and French tests. These details can help the Copilot team investigate whether language detection is working as intended. Reports posted in this user-to-user forum do not normally reach the product team directly.
Please note that this is a user-to-user support forum. Moderators and community contributors, including external Microsoft employees, cannot access back-end systems or directly make changes to Microsoft product features. Our role here is limited to providing technical guidance and possible workarounds based on the information available.
Hopefully this issue will be sorted out soon. Thank you so much for your patience!