Welcome to the McAfee Communities.You say you are current with all Windows updates, and your subscription is active. Please make certain that you are current with Internet Explorer 8. Whether you may use it or not, McAfee depends on it being current to function properly.To include any Add-ons as well.
You say last updated 3/13/2014? It seems that you have some corrupt files. I would do a clean uninstall/reinstall. Remove McAfee and all other security applications form your Add/remove programs 1st, then restart. Here is a link which gives you specific instructions on how to do so. It removes the listed McAfee Programs from 2005-2013. You may want to run the "McAfee Pre-Install Tool, (before) downloading and running the "MCPR Tool" here is the link for it; http://download.mcafee.com/products/licensed/cust_support_patches/McPreInstall.e xe