http://wiki.castleco...f_freeware_antivirushttp://wiki.castleco...freeware_antispywarehttp://wiki.castleco..._freeware_antitrojanhttp://wiki.castleco...eware_antikeyloggershttp://wiki.castleco...freeware_antirootkithttp://wiki.castleco...f_freeware_firewallshttp://wiki.castleco...re_behavior_blockershttp://wiki.castleco...f_freeware_sandboxeshttp://wiki.castleco...eware_virtualizationhttp://wiki.castleco...eware_analysis_toolsAbove is perhaps the most comprehensive list of top class freeware security products. How do they compare to the best $$ware in each category. If 10 is the best in the $$ category, here are my ratings for the corresponding best freeware. I.e 10 = the best freeware is as good (if not better) than the best payware.
Antivirus 8.5/10 - Each of the freeware antivirus as certain minor weaknesses compared to their paid bigger brothers
Antispyware 8/10 - Most of the freeware antispyware has no on-access scan except Spyware terminator.
Antitrojan 9/10 - Not quite sure, very few self declared anti-trojans these days... Trojanhunter vs BOclean?
Antikeylogger 7.5/10 - Possibly higher if we include sandboxes and behavior blockers against keylogger
Antirootkit 10/10 - The best generic antirootkits are free!
Firewall 10/10 - Comodo firewall , Webroot firewall , Online armor free etc help to raise the score.
Behavior blocker 9.5/10 - Many excellent choices depending on what you are looking for. Eqsecure,threatfire, SSM free, DSA etc etc are all top notch
Sandbox 9/10 - GesWall, sandboxie etc. Also SafeSpace lately.
Virtualization 10/10
Other misc security 10/10
This is just my estimation, what is yours? In short , i believe it is more than possible to use only freeware and remain as safe as one using $$ware only.