If you're on Windows then the built-in Firewall is "good enough"
Hmmm ... the shortfall on XP Firewall is that it protects you against unwanted and potentially dangerous
inbound traffic only.
It doesn't monitor outbound traffic, so if you do pick up a trojan or other unwanted program on your PC, XP Firewall will not spot it (or block it from) transmitting information from your PC to the internet.
For a good (free) Firewall that offers both inbound and outbound protection, take a look at
Sunbelt's Kerio Personal Firewall. It's a free download, fully featured for 30 days then drops back to restricted free functionality (IMHO you don't need the paid for stuff).
for antivirus I'd suggest Grisoft's AVG antivirus
Absolutely!
RC