Anti-Virus & Anti-Spyware Scanner

Kaspersky Free Online Scanner
http://www.kaspersky.com/virusscanner

GarbageScan(SecureMyWindows)
http://www.garbageclean.com/Products.asp

Spybot - Search & Destroy
http://www.safer-networking.org/en/download/index.html

Ad-Aware Personal
http://www.lavasoftusa.com/single/trialpay.php

Webroot
http://www.webroot.com/En_US/consumer-downloads.html