Avira

Basic protection doesn’t get any easier. It takes just two clicks to install and configure your free antivirus.

http://www.avira.com/en/avira-free-antivirus

Comodo Internet Security

Features

• Antivirus, Anti-Spyware, Anti-Rootkit & Bot protection
• Defends your PC from Internet attacks
• Detects and eliminates viruses
• Prevents malware from being installed
• Auto Sandbox Technology™
• Easy to install, configure and use
• Free to both business and home users

 http://www.comodo.com/home/internet-security/free-internet-security.php

AVG Free

Protection against viruses and spyware

http://free.avg.com/us-en/homepage

SpywareBlaster

Prevent the installation of spyware and other potentially unwanted software! Simple, effective, trusted.

http://www.javacoolsoftware.com/spywareblaster.html

KeeFox

KeeFox adds free, secure and easy to use password management features to Firefox which save you time and keep your private data more secure.

Think of KeeFox as a bridge or connection between Firefox and KeePass Password Safe, the most popular open source (and free) password manager.

http://keefox.org/

KeePass Password Safe

KeePass is a free open source password manager, which helps you to manage your passwords in a secure way. You can put all your passwords in one database, which is locked with one master key or a key file. So you only have to remember one single master password or select the key file to unlock the whole database. The databases are encrypted using the best and most secure encryption algorithms currently known (AES and Twofish). For more information, see the features page.

http://keepass.info/

Untangle

Untangle provides a powerful suite of Internet management applications for small-to-medium businesses and education institutions.

The Untangle Server is a multi-function firewall. It simplifies and consolidates the many network and security products that businesses need at the gateway to the Internet. Untangle comes as standard with these free, open-source applications:

• Web Filter – Prevents access to undesirable web sites
• Virus Blocker – Prevents viruses from reaching computers on the network
• Spam Blocker – Stops junk email from getting through
• Captive Portal – Enforces authentication and terms of use for internet access
• Ad Blocker – Blocks online adverts that waste network capacity
• Attack Blocker – Stops denial of service (DOS) attacks
• Phish Blocker - Protects people from identity theft "phishing"
• Spyware Blocker - Protects people from websites that install malware
• Firewall - Hides your network from the Internet
• QoS – Allows internet traffic prioritization
• Intrusion Prevention – Protects the network from hackers
• Protocol Control - Blocks protocols for online games, IM & P2P
• OpenVPN – Allows secure remote access to the internal network
• Reports - Shows who is doing what online

http://www.untangle.com/

OpenDNS

Everyone knows the internet is full of all kinds of content you may or may not want to see. You may have young kids at home or run a small business and don't want others to view content that you consider "inappropriate". Well OpenDNS is the answer! You can manually change your DNS on your computer to use OpenDNS servers instead of your normal DNS servers. With your OpenDNS account you can specify from the low, medium, or high filter level. You can even select custom and choose from 55 unique categories to block.

http://www.opendns.com/

ComboFix

ComboFix is a program, created by sUBs, that scans your computer for known malware, and when found, attempts to clean these infections automatically. Additionally ComboFix will display a report that can be used to remove malware that was not automaatically removed.

ComboFix is very powerful and should not be ran unless other tools such as Malwarebytes do not work.  Also due to the power of this tool it is strongly advised that you do not attempt to act upon any of the information displayed by ComboFix without supervision of someone who has proper training. Doing so may lead to problems that can prevent your computer from functioning normally.

Instructional Website:
http://www.bleepingcomputer.com/combofix/how-to-use-combofix

Download Links:
http://download.bleepingcomputer.com/sUBs/ComboFix.exe

http://www.forospyware.com/sUBs/ComboFix.exe

HijackThis

This handle tool will scan your registry and file settings on your computer and give you a detailed report and lets you choose what you want to remove. As some antivirus or malware scaners may find a useful tool like an ip scanner as bad. Select only what you want to remove.

IMPORTANT: HijackThis does not determine what is good or bad. Do not make any changes to your computer settings unless you are an expert computer user.

http://free.antivirus.com/hijackthis/

HouseCall

Think your PC is infected? HouseCall can quickly identify and fix a wide range of threats including viruses, worms, Trojans, and spyware. It is now faster, more powerful and browser independent!

http://housecall.trendmicro.com/

Malwarebytes

Probably the best free Anti-Malware software out today! Coworkers and I have been using this free software for well over a year now and recommend it to anyone that gets Malware on their workstation.  It will scan your hole hard drive or run the quick scan mode for a faster scan of just your critical Windows files. If you have some nasty pop ups or strange software on your computer that you think is Malware, Malwarebytes is for you.

http://www.malwarebytes.org/

Microsoft Security Essentials

Finally Microsoft has released free anti-virus software!!  This long over due free add-on to Microsoft Windows seams to work well. I have been using it since the Beta edition.  A few colleges and I have been running this software with good luck.  It doesn't seam to bog down your system and seems to work better then most free anti-virus.  No annoying pop ups, just good anti virus software.

http://www.microsoft.com/security_essentials/