Depuis quelques jours, il m'est impossible d'accéder aux applications Microsoft 365

Question

Que ce soit en cliquant sur un fichier, ou en ouvrant l'appli, rien ne se passe..... J'ai essayé de réparer Microsoft 365 sans résultats concernant mon problème.
Ceci concerne toutes les applis Microsoft 365 : Excel, Word, PowerPoint etc......
Pour info, pour vous donner des pistes, je rencontre le même problème à l'ouverture d'un fichier PDF avec Acrobat Reader. Par contre, si je choisis "ouvrir avec PDF24", le fichier s'ouvre normalement....

Aucune trace dans l'observateur d'évènements.

Merci d'avance pour votre réponse.

Jean-Paul

ASUS ZenBook 15
Windows 11 25H2 - à jour à février2026
Microsoft 365 Famille

Answer 1

Microsoft 365 applications that no longer open (no window, no error) despite a first repair attempt usually indicate a deeper problem in the Office installation rather than in each app individually.

Given that all Microsoft 365 apps are affected (Word, Excel, PowerPoint, etc.) and a similar symptom appears with Acrobat Reader, the most appropriate next step is a full Online Repair of Office, which is more thorough than the quick/standard repair and often resolves cases where no app will start.

Follow these steps on Windows 11:

1. Right-click the Start button and select Installed apps.
2. In the list, locate Microsoft 365 (or Office), click the ellipsis (…) next to it, then choose Modify.
3. In the repair dialog, select Online Repair (not just Quick Repair), then Repair.
4. Let the process complete and restart the PC when finished.

This performs a complete repair of the Office suite, replacing corrupted components that a basic repair may leave untouched.

If, after a full Online Repair and restart, the apps still do not open at all, the next escalation (based on similar issues) is:

1. Completely uninstall Microsoft 365 from Settings > Apps.
2. Restart the PC (not just shut down, but Restart).
3. Reinstall Microsoft 365 from the Microsoft account portal associated with the Microsoft 365 Famille subscription.

This combination (Online Repair first, then full uninstall/reinstall if needed) is the standard resolution path for situations where no Microsoft 365 desktop app will start.

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References:

• Repair an Office application
• we are sorry, but word has run into an error that is preventing it from working correctly. Word will need to be closed as a result. Would you like us to repair now? - Microsoft Q&A
• how i can fix the microsoft app problem - Microsoft Q&A