According to Microsoft, the major cause of this issue is a corrupted Navigation Pane settings file, called -“profile-name.xml”, where “profile-name” is the name of your Outlook profile. When this file gets corrupt, you cannot open the Outlook window and get the error message  “Cannot start Microsoft Outlook. Cannot open the Outlook window”. See the image below. To know how to resolve send/recieve issues in Microsoft Outlook 2010, click here.

1. Click on start button and search “Run” or press “Windows + R” for the “Run” dialog box . To reset outlook simply follow the instructions.
2. Type “outlook.exe /resetnavpane” command in the “Run” dialog box and click “OK”.
3. To delete the navigation pane settings file, type “%appdata%\Microsoft\Outlook” command in the run box and press enter. Double click on “Outlook” folder.
4. All configuration files for Microsoft Outlook are stored in this “Outlook” folder. Find and delete the “Outlook.xml” file.
5. To turn off Compatibility mode in Outlook 2010. Click on Start button and type “Outlook.exe” in the search field or Run box.
6. Right click on “Outlook.exe” and then click on “Properties”.
7. Now, click on “Compatibility” tab and clear “Run this program in compatibility mode for” check box. Click OK and try to start outlook.
8. If you still cannot open the Outlook window and the same “Cannot start Microsoft Office Outlook” error persists, try to “Restore the previous version of the PST file”. Enter “Outlook.exe” in the search field. Click on “Microsoft outlook 2010″. Right click on “Outlook.exe” and select on “Restore Previous Versions”.