Could you please quote the part where I said I don't scan my pc? I said there was nothing of the sort installed. I have loads of anti-malware software, mostly on bootable cds. On my hd I have (among other things) what you see in the attached pic. I have no active programs installed or running. When I feel my pc is not performing as it should I take action, last time I had to do any such thing due to malware was over a year ago. Based on being able to run my pc for over a year without getting all sorts of shit on it, it's worth it for me to not having to keep updating software and keeping them in use, taking up resources.
Here's a pro tip for you: If you want to do/try something you perhaps shouldn't (warez, new os, quad-boot, fishy sites that have useful stuff but you know are dangerous etc.), VMWare is your friend. It's free, (relatively) safe and flexible and available for Windows and Linux alike.