Switched from IE to firefox?

I`m useing vista. I have IE and switched to firefox. On IE i have norton 360 . I want to keep IE and norton360 on it. Also i want to have firefox. How do i put norton 360 on firefox and keep it on IE? I hope this is possible it would be nice to have IE with norton 360 and firefox with norton 360 both. What i see of firefox is that it is faster IE to me is kinda old. I feel that i will use firefox more than IE but i just want to keep IE you know just in case i need it. Also i bought this norton 360 at best buy for $70 bucks and i dont have a lot of extra money to spend to go out and buy a nother or something like it for firefox protection. Thanks