I’m not sure what is causing the problem, but we're seeing a rash of complaints with the following error:
Cannot start Microsoft Office Outlook. Unable to open the Outlook window. Invalid XML, the view cannot be loaded.
The users run Office Diagnostics in an attempt to fix it on their own but it finds no errors.
To fix this you need to close Outlook and reopen it using the /resetnavpane switch or find and delete <profile_name>.xml and restart Outlook. Outlook will recreate a new file with the default navigation pane folders. You will lose any customizations on the navigation pane, such as folders on the Favorites folder list
This problem may occur on Windows XP if you are running Outlook in Compatibility mode. Compatibility mode is NOT needed with any version of Outlook on any versions of Windows.
How to use the /resetnavpane switch
Close Outlook. At the Start search field on Vista or Windows7 Start menu or in the Start menu, Run command (Windows key + R), type or paste
Then press Enter (or OK button) to restart Outlook.
Note: Make sure there is a space between the words.
Delete the Navigation pane configuration file
If you are having problems using the switch, you can find and delete the XML file that holds the navigation pane settings. In the Start search or Run fields or in Windows Explorer's address bar, paste the following and press Enter:
This will open Windows Explorer to the folder where many of Outlook configuration files are kept. Find and delete the file named for your profile with the extension XML. Note that we highly recommend using the switch instead of deleting the file directly.
Microsoft KB articles
Error starting Outlook: “Cannot start Microsoft Office Outlook. Cannot open the Outlook window.”.
See Error with the To-Do Bar's Task list if the error is "The operation failed. An object could not be found."