Below are links to programs that I have personally tested and recommend as being useful to most computer users. All of the listed software may be used free of charge as they are rated as Freeware.

Anti-Virus Solutions
Avira AntVir Personal Anti Virus
Avast Home Edition Anti Virus

Microsoft Security Essentials
PC Tools Threatfire


Anti-Spyware Solutions
A2Squared Anti-Malware
Spybot Search & Destroy
Spyware Blaster
Super Antispyware
RemoveIt Pro
Malwarebytes Anti-Malware
Anti-Malware Toolkit

Anti-Rootkit Solutions
Panda Anti-Rootkit
Sophos Anti-Rootkit
McAfee Avert Labs Rootkit Detective
Rootkit Revealer
Trend Micro Rootkit Buster

Chat Client Utilities
Trillian
X-Chat 2 For Windows IRC Client

Computer Utilities
Winpatrol
Speed Fan
CCleaner
Defraggler
CachemanXP
Easy Cleaner
Auslogics Disk Defrag
Ultimate Windows Tweaker
Actual Booster
Tweak UI
Winrar
JavaRa
Notepad
Core FTP

Audacity
DVD Shrink
Hidden Utilities XP
Trend Micro HijackThis
Secunia Personal Software Inspector
Microsoft Baseline Security Analyzer 
AnVir Task Manager (Free Version)
Ashampoo Burning Studio 6 FREE 

Comodo Time Machine

Personal Firewalls
Online Armor Personal Firewall
Comodo Personal Firewall
Outpost Firewall
 

Security Suites
Comodo Internet Security

Web Browsers
Mozilla Firefox
Google Chrome

More products will be added as I test them out to ensure they are worth adding.

Windows 7 ISO x86 & x64 Official Direct Download Links

Untested Software
The following links contain software that I have not yet tested.
Browsers
Anti-Spyware Utilities
Anti-Virus Utilities
Audio & Video Utilities
CD/DVD Utilities
Cleanup & Tweaking Utilities
File Sharing Programs
Firewall & Security Programs
Instant Messaging & Chat Programs