Useful Free Software and Shareware links

7-Zip:

An open source (freeware) program that decompresses and archives in most common formats e.g. .zip and .rar plus others.

http://www.7-zip.org/ 

Antivirus

Panda - link to website
Scan your system for viruses online. Free. No software to install

AVG - link to website
Full, free antivirus software download

Firewalls

ZoneAlarm - link to website
Probably the best known free firewall - make sure you choose the link for the free product

Malware Destruction

Spybot Search and destroy - link to website.
Free application to scan for spyware, adware, hijackers and other malicious software.

Ad-Aware Personal - link to website
Free version to scan for spyware adware etc

Web Browsers

Mozilla Firefox - link to website.
Free, fast and efficient. Basic version is simple and easy to use. Lots of add-ons available from their site to make the application feature rich.

Opera- link to website.
Free version has adverts. If you buy the product the ads are removed. Fast and efficient. Feature rich interface which some may find overwhelming.

Screen Capture

HoverSnap v0.8 - link to website
Free software allowing the user to capture whole screen or active window.

Office software

OpenOffice - link to website.
Free. Claims to be able to duplicate nearly all features found in Microsoft Office.

Data encrytption software

Iron Key - link to website
Encrypts single files - free version is called iron key - other paid versions with advanced functions (e.g Silver key) are available

Other link sites

all-internet-security.com/ - link to website
Can't find what you want above then try this site - they have links to hundreds of freeware and shareware security programs