it may be a OEM installation ans has 3 months left on the subscription if you have upto a year then your lucky and perosnally I would keep the Norton.
Make sure you registar the norton by dropping the Help menu down this will help you get the full updates.
If you have norton with the laptop also on a CD then unintall the Norton from laptop fully by removing Live update, symantec & norton lines in Add/remove (control Panel) then reinstall McAfee.
Come McAfee expires either stay or remove and put norton back.
Perosnally I have worked with Norton from D1 and prefer it but its what your use to at the end of the day.
What not to do is "Not" to run Both or you will crash or cause problems/Conflict's galore.
Hope I helped