When you examine the Windows taskbar, the Outlook icon is not displayed even though Outlook is running and there is an Outlook icon in the notification area of the taskbar. The following figure demonstrates this problem.
This scenario occurs when you have enabled the Hide When Minimized option for Outlook and you minimize the main Outlook window. This option is available when you click the Outlook icon in the notification area.
To change your Outlook configuration so that the Outlook icon is displayed in the taskbar when Outlook is running, use the following steps:
Start Outlook if it is not running.
Click the Outlook icon in the notification area.
Select Hide When Minimized.
The Hide When Minimized option is controlled by the following registry data.