Slow computer

hi
I hope someone can help me with a problem I have with my computer.Ever since I put norton anti virus on it it has slowed up an awfull lot. The floppy drive is making noise aswell even when there is no floppy disk inserted and the computer is just sitting there and turned on ,obviously.That’s probably a different problem but it’s very annoying. In relation to the first problem I was wondering whether I need more ram or something like that because the computer seems to be using the hard disk alot more than it used to and I was wondering whether it was because the computer is using too much virtual memory.Any suggestions would be very helpful if you wouldn’t mind.

Thanks