Anti virus software (Completely free)
http://www.avast.com
http://free.avg.com AVG
http://www.free-av.com/ Avira AntiVir
Online anti virus software:
http://www.cloudantivirus.com/en/ Panda Cloud Anti-virus
Standalone scanner
http://vil.nai.com/vil/stinger/
AV and Anti-spyware?
Windows Defender http://www.microsoft.com/windows/products/winfamily/defender/default.mspx
Microsoft Security Essentials http://www.microsoft.com/Security_essentials/ "Microsoft Security Essentials provides real-time protection for your home PC that guards against viruses, spyware, and other malicious software."
Anti-spyware tools
http://www.emsisoft.com/en/software/free/ A-squared / Anti-Malware Free edition
http://www.download.com/Ad-Aware-2008/3000-8022_4-10045910.html?tag=lst-1&cdlPid=10844457 ad-aware
http://download.cnet.com/Spybot-Search-amp-Destroy/3000-8022_4-10122137.html Spybot
Lots more links and information here: http://www.moneysavingexpert.com/shopping/free-anti-virus-software
