When using Outlook, it is possible to have the Desktop and the OWA plugin both showing as email sidebars. Typically this is not desired, although it is a supported configuration. If a user is showing both sidebars and would like to disable one, they can choose the version to keep by using this article.
To delete the desktop sidebar, the installer can be run, and the question to Repair or Remove the software will be displayed. Choose Remove. An alternate method is to uninstall from the Control Panel. A third alternative is to disable the plugin in Outlook.
To remove the OWA plugin, choose the File Menu from within Outlook, and then use the Manage Add ins link at the bottom of the white area to open the OWA add in configuration screen. Uncheck Cirrus Insight and return to email.