Anti virus protection for windows 7

Security on Windows 7 relies heavily on its users. For an advanced users, anti virus protection on windows 7  is simply an additional. On their hand a windows 7 without anti virus can be more safer rather than a computer with fully protected windows 7 on someone else hand. But again its about experiences, the advanced users could not be on their level now without their experiences. For example they knew when to open or not to open an email from a suspicious user, or when to click or not to click an interesting thing on a web page, something was happened in the day where they were downloaded or clicked the wrong things, so they stay alert until now.

But call me over protective, because I'm not an advanced user and somethings always happening to my windows 7, even tough i have a running anti virus on my Windows 7, that's why i add 2 more protection system to work along with my regular anti virus. Not sure if this is a great combination or not, but here's what I've put on my windows 7.
1. Avira - anti virus protection. 
I've using Avira since the earlier 2005 and its save me a lot from viruses, although I've got many hard time recovering documents and system when there are viruses infecting systems files.
2. Threatfire - bad behavior protection
They call them self a Zero-day malware protection, a protection system based on malware bad behavior.
When there's something suspicious working even in the background, threatfire will react and sending an alert windows contain action for the current suspicious application.
3. Comodo Personal Firewall - firewall protection
A replacement for windows native firewall, it will control applications running on our windows 7. When something suspicious occur, comodo firewall will hold the applications until further action is selected. 

There's no significant reduction on performance caused by those 3 protection on my windows 7, I guess because nowadays computers and laptops are generally on better specs, high memory and processor.