If you were using a trial version then it expires after 30 days and you either have to then subscribe or uninstall the software and try something else.
What Peter says is right , I just happened to verify your account, the McAfee Internet security suite, you obtained through Toshiba was a trail version valid for 30 days and got expired on the 15 of this month. So, in order to stat protected , please visit our home page choose your protection suite & then install the same . http://home.mcafee.com/store
On the other hand, if you had purchased a complete subscription for a year or so from Toshiba , please contact them for any order no for the same and contact our Customer service reps , so that they would help you to activate the same and get it installed accordingly.