Meta will discontinue its Messenger app for Windows and macOS on December 15. After this date, Mac users will be redirected to Facebook.com for messaging, while Windows users will be encouraged to use the Facebook desktop app. Access to the Messenger desktop app will be blocked, and users will need to uninstall it. The mobile version of Messenger will remain operational. Users should enable secure storage for encrypted chats to ensure successful transfer of chat history. They are also advised to back up important files and photos, check Messenger-only accounts, and prepare for workflow changes.