Get free PC security software

• AVG Free
• Malwarebytes   
• Avast Home Edition     
• Spamfighter   
• Comodo Internet Security      
• Mailwasher   
• Agnitum Outpost Security Suite   
• Comodo Antispam   
• Lavasoft Ad Aware Internet Security     
• McAfee Site Advisor   
• Microsoft Security Essentials   
• Trend Protect  
• Avira Antivir      
• Finjan Secure Browsing   
• Google Pack   
• Sandboxie   
• Comodo Antivirus      
• Comodo Firewall   
• Bitdefender      
• PC Tools Firewall Plus   
• Panda Cloud Antivirus      
• Zone Alarm   
• Windows Defender      
• Sumo Lite   
• Spywareblaster      
• Trend Micro’s Rubotted   
• Spybot Search and Destroy   
• PC Tools Threatfire   

There are two approaches to building a security toolkit. There’s the all-in-one method using a suite of programs from one company, and there’s the ‘pick-and-mix’ method where individual programs are chosen to give best-of-breed protection.

Both approaches have pros and cons; the all-in-one scheme can mean fewer programs to maintain, and the components should all work seamlessly together. The pick-and-mix method can be more flexible, but there’s always a chance of incompatibilities between programs.

Hit the suite spot
Free security suites, such as AVG Free, Avast Home Edition, Comodo Internet Security, Agnitum Outpost Security Suite and Lavasoft Ad Aware Internet Security  don’t include all the components mentioned above, and they also differ from each other.

For example, AVG includes anti-virus, anti-spyware, email checking and browser protection, whereas Avast has protection for P2P file sharing, network activity and instant messaging. Comodo and Agnitum include a firewall, and Agnitum even has an anti-spam filter.

Standalone anti-virus programs include Microsoft Security Essentials, Avira Antivir and Google Pack, which includes a free cut-down version of PC Tools’ Spyware Doctor with Antivirus.

Comodo’s anti-virus program is also available as a standalone program and Bitdefender has a free version, although the company doesn’t advertise it prominently. One program that’s a little different from the rest is Panda Cloud Anti-Virus, which uses a database of threat information stored online in the ‘cloud’.

Who’s spying on you?
Practically all free anti-virus programs now include at least some anti-spyware protection, as the difference between these threats has become blurred; viruses can install spyware to monitor keystrokes or steal personal information from a PC, for example.

A good example is Microsoft Security Essentials, which includes the Windows Defender anti-spyware program. (If you install Security Essentials on Windows Vista or 7, the built-in version of Windows Defender is turned off). Windows Defender is included in Windows Vista and 7. Windows Defender for XP can be found here.

If you want some extra protection against spyware that shouldn’t interfere with any anti-spyware modules in anti-virus programs, Spywareblaster is a good choice. This helps stop known spyware, such as diallers and stops cookies from untrusted sites installing in the first place.

Spybot Search and Destroy is an old favourite, too, for scanning a computer for existing spyware. However, its Tea Timer resident protection module can sometimes conflict with other anti-spyware programs.

Get what you don’t pay for
It’s important to check exactly what features each program you choose includes, and also how it differs from the paid-for version if one exists. Some companies, such as AVG, Avast and Panda, make the differences clear, but in other cases (such as Malwarebytes) you don’t find out until you’ve installed the software and find that some features are unavailable.

Avast and AVG don’t give you the firewall or anti-spam features in the free products, and the free version of Malwarebytes and Bitdefender don’t have resident protection, with the result that they only scan for viruses when you tell them to.

Resident protection (also called real-time or on-access protection) is an important feature to prevent infections getting onto a PC in the first place – when any file is opened or downloaded, the software checks that it doesn’t contain any malicious software.

Sometimes the most useful features are disabled in the free versions; Spamfighter and Comodo Antivirus don’t have automatic updates, for example.

Adverts or annoying ‘nag’ screens that try to get you to upgrade to the paid version are also understandably common in free programs, although it isn’t as bad as it used to be. AVG has a notification box with an advert at the bottom of the main window that can easily be hidden, but other programs may grey out features or show adverts in menus.

Another trick free programs use is to offer trial versions of other software. For instance, during setup, Comodo optionally installs a six-day trial of the Geek Buddy helpline application. AVG has a PC Analyzer module that is really just an advert for its tune-up software. Some free programs also require registration, including Avast and Bitdefender.