If its Norton 360 v3 then its ok for three computers.Have you tried an online chat with a Norton rep?Have you tried a reinstallation of Norton?Has this happened only since the Norton installation?What is your operating system.
i had an online version which expired. igot 360 v.2 with a new laptop for my son. Safari certainly took over as default before norton debacle. i talk 2 hours with norton, 1 hour with pc performance , no help. i may still have someof the old norton on thepc. but i have tried over and over toinstall 360 , it says 'met a corruption' contact symantec. already done it , no good.
i don't know what he meant by contact windows. pc performance is £10 a month help package pc world. they have often been v. good. but can't help with this. they say reboot, but in my experience one loses a lot of data.