Free Online Scans:
Windows Live OneCare safety scanner is a free service designed to help ensure the health of your PC.
eTrust Antivirus Web Scanner
HouseCall (Trend Micro)
Panda ActiveScan
Free Virus Removal Tools (at Kaspersky)
Test Your Browser's Security Now! (powered by Scanit)
Free Software Tools: Secunia PSI (Release Candidate 1): Secunia PSI detects installed software and categorises your software as either Insecure, End-of-Life, or Up-To-Date. Microsoft Windows Defender
Windows Live Safety Center (a free service designed to help ensure the health of your PC)
Windows Live OneCare
Microsoft Baseline Security Analyzer (for IT Professionals) Microsoft's Malicious Software Removal Tool
AVG Antivirus v8 (Free): a fine AV program.avast!:another excellent, free Antivirus avast! Virus Cleaner: avast! Virus Cleaner is available free for every user. This tool will help you remove selected worm infections from your computer.
Ad-Aware SE Personal SpywareBlaster
Symantec Removal Tools 
Here are some excellent MS MVP security-related pages that I have found helpful:
 Donna's SecurityFlash (PC & Internet Security Blog by Security MVP Donna Buenaventura)
*See Donna's superb "Calendar of Updates" site as well for more security links and security-based forums! 
LandzDown Forums: excellent forums for your security-related questions, problems and concerns. Security Garden (by Corrine, MVP Security)
3 important steps in creating a password (by Donna Buenaventura, MVP)
Siljaline's IE & Security Blog (by AumhaVSOP Randy Knobloch)
Safe Browsing and Security Guide- Microsoft Internet Explorer (By Sandi Hardmeier, MVP)
Blocking Unwanted Parasites with a Hosts File (by MVP Mike Burgess)
Parasites & Other Security Issues (at Jim Eshelman's Windows Support Center)
5-Minute Security Advisor - The Road Warrior's Guide to Laptop Protection
Before You Connect a New Computer to the Internet (CERT® Coordination Center) Steps that you can take to help identify and to help protect yourself from deceptive (spoofed) Web sites and malicious hyperlinks Personal Firewall Reviews (links to vendors and reviews of many software firewalls) HiJackThis Tutorial (How to use HijackThis to remove Browser Hijackers & Spyware) Safe Hex - (Safe Computing Tips) Virus Threat Center: (daily virus updates, virus alerts, security advisories, online news, white papers, case studies, Webcasts, and downloads.) The Antivirus Defense-in-Depth Guide Spyware Warrior: (Rogue/Suspect Anti-Spyware Products & Web Sites. Be informed!)
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The latest information on Windows-specific security tools, patches, flaws, technical information and assistance in proactive measures to deal with security issues.
This page last updated: February 21, 2008 | 
It is more important than ever to educate ourselves on the basics of security so that we can keep our PCs "running clean".