First as the topic is anti virus i shall answer this first. As someone else mentioned nod32 is one of the best on the market with Kaspersky, although i recommend kaspersky 6.0 and not 7.0. If you are looking to use a free AV then use either avast or AVG as also mentioned.

Next you need a firewall which i recommend using Zonealarm as its free and is easy enough to use for noobs. Google around if you want to do some of your own testing.

There is also a problem with adware, spyware and malware. As also mentioned above use spybot search and destroy. In conjunction with this i recommend using adaware personal and ccleaner. All these software products are free for personal use.

When downloading files and if you are unsure if the content is safe the scan with an online scanner like virustotal.com.

Happy surfing :rastasmoke: