What are the best free resources to protect your pc from online attack?

where can i find the best free anti virus protection online or do i need to buy norton or similar type products? All advice on this would be greatly appreciated. Thanks

What are the best free resources to protect your pc from online attack?internet

avast avg/ewido comodo ...

What are the best free resources to protect your pc from online attack?network

AVG Antivirus - Free Antivirus Software

(CNET: "AVG Anti-Virus Free Edition is the most popular free solution available at no cost to home users and provides the high level of detection capability that millions of users around the world trust to protect their computers.")

Ad-Aware - Free Antispyware Software

(CNET: "One of the first applications built to find and remove adware and spyware, Ad-Aware 2007's excellent reputation is well-justified.")

Spybot Search%26Destroy - Free Antispyware/Antitrojan Software

Some REALLY great features of Spybot Search%26Destroy: Its ability to help your PC block known spyware/hijacker sites with Immunize feature, a Secure Shredder for truly removing files from your PC, and Startup, which allows you to view the files starting with Windows.

SuperAntiSpyware

SUPERAntiSpyware Free Edition is 100% Free and will detect and remove thousands of Spyware, Adware, Malware, Trojans, KeyLoggers, Dialers, Hi-Jackers, and Worms. SUPERAntiSpyware features many unique and powerful technologies and removes spyware threats that other applications fail to remove.