More information would help. Is the icon a square one (2009 version) or shield-shaped (2010 version) and what is your operating system and service pack (Right-click Computer (Vista/Windows 7) or My Computer (XP) and select Properties, and what is your default browser and version (open browser and go to Help/About)?
Also do you have any other problems or pop ups - any hint of an infection?
Any other security software installed or perhaps was installed earlier on?
What happens a) when you double-click the taskbar icon and b) right-click it?
Do you still face difficulty in opening security center ? If so please let us know so that we could get it fixed for you.
McAfee Online Community Moderator