I always use a “FREE” anti-virus (AV) and I never had any problem with it.
Free doesn’t mean that it performs mediocre compared to a “LICENSED” anti-virus. I also install free AV to all of my customer’s PC. Setting up the security of a PC properly with any AV is the key to a troublesome PC performance.
About Quarantine: It doesn’t matter if your application is quarantined by the AV and not cleaned, you can download a clean copy of that again from the internet. If your licensed program comes on a CD or DVD, you already have a clean copy to begin with. For example, you are infected with sality, your paid-for AV, let’s say Symantec Endpoint Protection (SEP), won’t be able to repair the damage but Kaspersky’s FREE sality killer can (based from actual experience).
Not all licensed anti-virus are the best for your needs. Free AVs like Avast! and Panda Cloud do a good job too and I’ve been using Panda for more than a year now without any complaints.
The main concern of doubters of free AVs is, when you use free AV, there are some lacking on its feature because its free. Thus, when you buy a licensed AV, there are key features that are activated that almost completely protect you from threats. But please also take note that if you activate all of these features which may not be all necessary for your needs, it may result to some system slowdown.
An added advantage of licensed AVs is you are able to get support from the AV distributors, but if you have a stable system setup, its very rare to need their assistance anyway.
Malware Bytes Anti-Malware (MBAM) has a free version too and it’s good enough for me. When it comes to removing malware, Malwarebytes is one of the best, no argument about that.
List of Free AVs and AV Tools that I use and is installed on my systems:
1. Panda Cloud Antivirus/Panda Cloud Cleaner
3. Malware Destroyer
4. Hijack Hunter
5. USB Guardian
I have backups of my installers on CD/DVD and External USB Drive so losing them through an infection is least of my concerns.
The most important thing to remember is to keep your AV definitions always updated to be able to cure even the newest variants of viruses.