Here is some advice and recommendations on software to prevent Malware.

Use an AntiVirus Software: It is very important that your computer has an AntiVirus software running on your machine.  This alone can save you a lot of trouble with malware in the future. Here is a list of some free versions to try:

• AVG AntiVirus
• Avast Antivirus Home Version
• Antivir Personal

Use a Firewall:
It is also very important that you use a Firewall on your computer. Without a firewall your computer is susceptible to being hacked and taken over. Simply using a Firewall in its default configuration can lower your risk greatly. Here are some free and versions that provide better security than the Windows Firewall (NOTE: If you are running Vista or Windows 7 then the firewalls included with those operating systems are more robust than Windows XP).

• Online-Armor
• Outpost Firewall
• Sunbelt Personal Firewall

For a tutorial on Firewalls and a listing of some other available ones see the link below:

Bleeping Computer Understanding and Using Firewalls

Install SpywareBlaster:
SpywareBlaster will added a large list of programs and sites into your Internet Explorer settings that will protect you from running and downloading known malicious programs.
A tutorial on installing & using this product can be found below:

Bleeping Computer Using SpywareBlaster to protect your computer from Spyware and Malware

Install Winpatrol:
Use Winpatrol to take control of your PC and provide another layer of security.
Help file and tutorial can be found Here

Block unwanted parasites with a custom hosts file

Update Windows:
It is important that you visit Windows Update regularly or set your computer to receive automatic updates. This will ensure your computer has always the latest security updates available installed on your computer. If there are new updates to install, install them immediately, reboot your computer, and revisit the site until there are no more critical updates. If you cannot remember to do this then make sure Windows is set to automatically download and install updates.

Update all of your Anti-Malware programs regularly:
Make sure you update all the programs I have listed and the ones you are currently running regularly. Without regular updates you Will Not be protected when new malicious programs are released.

Keep your applications up to date:
Use Secunia Personal Software Inspector to help stay on top of application updates that could leave your PC vulnerable to attack.

Regards,
Dave aka IndiGenus