SCSIraidGURU

Avast Pro 4.8 is not that expensive and fantastic. Avast has a free version.

On your Router, you can enable MAC filtering, and other features to secure your computers. Get the latest firmware for the router. MAC filtering is simple. Each NIC has a MAC address. It is the ipconfig/all physical address. You enter your computer MAC addresses and only those computers can access the router. On the Windows firewall, advanced security can be set for only your subnet to gain access through the firewall for file and print sharing. It is not perfect, you can spoof it. However, most users will find fully open wireless routers to enter. Also, if you use wireless, turn on all the security to highest levels on the router and computers. Change the router IP address to something other than default. Use a 13 alphanumerical password for the router. Use passwords on all your computers and don't cache them in IE. Keep A/V software up to date. Use UAC to protect Vista. You can disable UAC for installing. Enable it for using.