What operating system and service pack are you using and what version of Internet Explorer is installed, whether or not you use it?
If your have a beta version of Internet explorer installed uninstall it immediately and install the latest version for your system, IE9 for Windows 7 or Vista and IE8 for XP.
SecurityCenter is an actual IE page and depends on a working broswer set to its default settings. However it is fine if you wish to use an other browser as your default.
FYI: You can always download a fresh copy of the software from your online account.
Just sign in: https://home.mcafee.com/root/myaccount.aspx