CCleaner is a freeware system optimization, privacy and cleaning tool. It removes unused files from your system - allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. Additionally it contains a fully featured registry cleaner. But the best part is that it's fast

(normally taking less than a second to run) and contains NO Spyware or Adware! :) http://www.ccleaner.com/

Defraggler. It differs from other defrag tools on the market, by enabling you to quickly and simply defrag the files you want to, without having to process the whole drive. Simply run it, select the file and defragment in seconds. No more struggling with the Windows defragmentation tool! http://www.defraggler.com/

Firefox . The Firefox Web Browser is the faster, more secure, and fully customizable way to surf the web. www.mozilla.com

Opera gives you the full Web experience everywhere. www.opera.com

a-squared Free 4.0 . Scans your computer for malicious software (Malware), including Trojan Horses, Dialers, Worms, Spyware, and Adware. A-squared Free is specialized in finding and removing them securely. The disk scan checks all files on your system disks for Malware. The scanner scans for Spyware Traces. Currently more than 1.2 million different types of Malware may be detected and removed.

homepage / http://www.emsisoft.com/en/software/free/ download page / http://download.cnet.com/A-squared-Free/3000-2239_4-10262215.html

There is lots at majorgeeks.com

Avira AntiVir Personal - FREE Antivirus Basic protection Protects your computer against dangerous viruses, worms, Trojans and costly dialers. New: Basic Anti-Spyware. http://www.free-av.com/

i know mate but want ppl to post stuff they use/used and would recommend to others

COMODO Internet Security . Internet Security combines the power of COMODO's award-winning Firewall and AntiVirus software to protect your PC from malicious software and Hackers. Best of all it's FREE! http://www.comodo.com/

SpeedFan is a program that monitors voltages, fan speeds and temperatures in computers with hardware monitor chips. SpeedFan can even access S.M.A.R.T. info and show hard disk temperatures. SpeedFan supports SCSI disks too http://www.almico.com/speedfan.php

Malwarebytes is a site dedicated to fighting malware. Malwarebytes has developed a variety of tools that can identify and remove malicious software from your computer. When your computer becomes infected, Malwarebytes can provide the needed assistance to remove the infection and restore the machine back to optimum performance. http://www.malwarebytes.org/

RocketDock is a smoothly animated, alpha blended application launcher. It provides a nice clean interface to drop shortcuts on for easy access and organization. With each item completely customizable there is no end to what you can add and launch from the dock. http://rocketdock.com/

TwistedPixel is a MediaMonkey, WinAmp, WMP MCE 2005 Visualization that uses a video card's 3d capabilities and Microsoft's Direct3D to produce flowing images in reaction to music http://www.visolu.com/TwistedPixel/

Torrent is a lightweight and efficient BitTorrent client for Windows or Mac with many features. www.utorrent.com/

Paint.NET is free image and photo editing software for computers that run Windows. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects, and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials, and plugins. http://www.getpaint.net/

LogonStudio allows Windows XP/ Vista users to edit, change, and apply new logon screens. ... See how LogonStudio can take a boring logon and bring it to life www.stardock.com/products/logonstudio/

Opera turbo is a free browser speed up browsing for people that dont have a fast internet connection it can be found at www.opera.com

FireTune for Mozilla Firefox The original speed optimizer for Mozilla Firefox. http://www.totalidea.com/product.php?Product=FireTune