Users of Microsoft Outlook have complained about receiving an error stating “Cannot start Microsoft Office Outlook. Unable to open the Outlook window”. Upon running Microsoft Office Diagnostics to fix this, users would get a message saying there are no errors. This leaves user without any solution to the problem, and they cannot open Microsoft Outlook to send or receive emails either. This problem is caused by a corrupt .xml file (which is used to store your personal settings for the Outlook Navigation Pane) and can be fixed in the following manner:
• 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 “outlook.exe /resetnavpane”
Additionally, when following the above mentioned procedure it is recommended to make sure there is a space between the words.
After you have inserted the proper line of command it is required to press Enter (or OK button) to restart Outlook. Your navigation pane will be reset to the default settings, i.e. without some personal touches such as your favorites.
• 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 (). It is recommended to use the switch rather than delete the file directly.
Once you have completed either of these steps, your navigation pane will be restored, and you will no longer experience the above error. However, all customizations that you have made to the navigation pane will be lost and will have to be redone.