You definitely need a good antivirus if your going to be surfing the web and with that said I would uninstall McAfee so fast it would make you head spin. It misses quite a bit of stuff and is a resourse hog.

There are a few really good free antivirus programs out there and here's a couple that are popular. Google them both and you'll find lots of good stuff about each.

Avast free home version - What I've been using for about 2 years now and really like.

Avira AntiVir - Lots of great features


You also might want to use a program called SpywareBlaster that helps prevent the installation of spyware and other potentially unwanted software on you computer. Easy to use and set up.

If you use Internet Explore make sure to keep your computer up to date via Windows update to keep it safe or switch to another browser like Firefox, Opera...........

Too much info I know but it's a unsafe web surfing world out there but better safe than sorry.