Free Software Listing.

[PDQ]

Anti-Virus,
AVG Anti-Virus Free Edition download and installation is only available for single computer use for home and non commercial use.
http://free.avg.com/download-avg-anti-virus-free-edition

Avast, This edition is FREE OF CHARGE for non-commercial & home use only.
http://www.avast.com/eng/avast_4_home.html

ClamWin is a Free Antivirus comes with an easy installer and open source code.
http://www.clamwin.com/

Anti-Malware/Spyware/Adware,

Malwarebytes have created an easy-to-use, simple, and effective anti-malware application.
http://www.malwarebytes.org/mbam.php

Spybot - Search & Destroy detects and removes spyware, and is considered one of the best.
http://www.safer-networking.org/en/spybotsd/index.html

RunAlyzer is from the people who made Spybot - Search & Destroy allows you to view and edit all the spots where Windows looks for programs or services to start.
http://www.safer-networking.org/en/runalyzer/index.html

Trend Micro HijackThis generates an in-depth report to enable you to analyze and fix your infected computer.
http://free.antivirus.com/hijackthis/

Trend Micro CWShredder is the premier tool to find and remove traces of CoolWebSearch – the name for a wide range of insidious browser hijackers– from your PC.
http://free.antivirus.com/cwshredder/

Windows Defender, from Microsoft helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software.
http://www.microsoft.com/windows/products/winfamily/defender/default.mspx

Security Related,

KeePass, is a free open source password manager, which helps you to manage your passwords in a secure way.
http://keepass.info/

TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted drive.
http://www.filehippo.com/download_truecrypt/



Chat,
mIRC is a popular Internet Relay Chat client used by millions of people, and thousands of organizations, to communicate, share, play and work with each other on IRC networks around the world.
http://www.mirc.com/

Pidgin is an easy to use and free chat client used by millions. Connect to AIM, MSN, Yahoo, and more chat networks all at once.
http://www.pidgin.im/

Chat on Windows Live™, Yahoo!®, MySpaceIM, AIM®, Google™, ICQ®, Jabber, Skype™, IRC, and manage your Email, Facebook, and Twitter™!
http://www.trillian.im/