In Microsoft Outlook 2010, the conflict handling feature is enhanced to provide conflict resolution in online mode. This feature resolves conflicts when different versions of the same item exist on the server and on the client.
In some scenarios, earlier versions of Outlook clients display errors when you save an item. The errors resemble the following:
The item cannot be saved because it was changed by another user or in another window.
The item cannot be saved because it was changed by another user or in another window. Do you want to make a copy in the default folder for the item?
However, under those same conditions, Outlook 2010 does not generate conflict errors.
The new Outlook 2010 online mode functionality results in most conflicts being resolved upon save. Outlook does this by using the same conflict resolution logic that is used to resolve changes during Cached Exchange Mode synchronization. The goal of automatic conflict handling is to never display conflict errors to the user. However, in some scenarios, users may expect to see the conflict messages that they received in earlier versions of Outlook. For example, when multiple users update the same meeting in a calendar public folder. In this scenario, the Outlook 2010 conflict resolution functionality overrides the public folder setting. Therefore, the Exchange users do not see conflict messages, even when the same item was modified at the same time by two or more different users.
How to disable the new Outlook 2010 automatic conflict resolution behavior
Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
To revert to the Outlook 2007 conflict resolution behavior, create the following registry value: