You use Microsoft 365 Copilot.

Microsoft provides centralized activity management controls through the My Account portal, which allows users to manage privacy settings, activity history, and data associated with Microsoft 365 services, including Copilot. When the requirement is to delete all conversations with minimal effort, the most efficient method is to use the account-level activity management tools rather than deleting conversations individually.

The My Account portal enables bulk management of Copilot activity data, allowing users to clear conversation history in a consolidated manner. This approach aligns with Microsoft’s privacy-by-design framework, giving users control over their AI-generated interaction history without requiring administrative intervention.

Using the Copilot web or desktop app would typically require manually deleting conversations one at a time, increasing effort. The Windows 11 Settings app is unrelated to Microsoft 365 Copilot data management.

Therefore, to delete all Copilot conversations efficiently and with the least amount of effort, the correct approach is to use the My Account portal in Microsoft 365.