A common trick of computer companies such as Acer, Emachines, Gateway, etc. is to sell you a machine preloaded with Norton Antivirus which gives you 6 months of free protection.
To be honest the first thing our techs do when they see Norton installed on machine is convince the client to remove it. It takes up way too much memory and slows down most machines.
Want to save a couple bucks? Try these guys instead: