One thing thats worth mentioning if you do decide in getting a Laptop, this lends you the possibility for you to use it anywhere you
want in your home via a wireless network such as your kitchen, backyard, bedroom, living room etc.
I'd suggest going to a store and play around with both versions and choose a suitable preference, there are plus and minuses
in both versions.
In regards to getting a PC rather than a MAC, PC's have more software that is designed around the OS
and yes you should always have an anti-virus program running in the background, fortunately in conjunction with the faster
working computers today and the newly designed anti-virus programs such as Norton 2009 there is little if any bogging down as was noted
and comfirmed in the past.