Article ID: 2264398 - View products that this article applies to.
When you start Outlook with a profile for an Exchange mailbox, you may receive the following error:
Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The connection to the Microsoft Exchange is Unavailable. Outlook must be online or connected to complete this action.
The action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.
The name cannot be resolved. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.
This issue occurs when the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders registry key does not contain all of the required data. Specifically, these problems occur if the AppData string value is missing from this registry key.
NOTE: The \User Shell Folders key also contains a string value called Local AppDatawhich is different from the value called AppData. The value that causes this problem (if it is missing) is the AppData value.
To resolve this issue, import the User Shell Folders registry key from a working Windows User Profile.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(https://vkbexternal.partners.extranet.microsoft.com/VKBWebService/ViewContent.aspx?PortalId=1&scid=kb;en-US;322756)How to back up and restore the registry in Windows
(http://go.microsoft.com/fwlink/?LinkId=151500)for other considerations.