I have put some selective security updates for XP.. FWIW.. There are security holes in XP, IE combo so worth downloading some stuff.. Needless to say, Antivirus and firewall on PC now a days is a must.. but I am still amazed to see some very risky surfing habits of people..
service pack 1 gives you USB2 support which is very usefull for digital camera transfers and ext USB harddrive transfer i think the transfer rate is 450 mbs