Okay. I know, that Avira's AntiVir has the BEST (better than Kaspersky's) heuristic code analyzer / proactive defence against unknown malware... so, I'll pick it as an (free) anti-virus.
But what about anti-spyware? I was trying to use Spyware Terminator with Avira's AntiVir, but had a conflict. you can tell me how to avoid such conflict with these two programs. but the thing I really want to know, is that - what (free) anti-spyware (with real-time protection) is the best and will suite my Avira's AntiVir?
Also, which (free) firewall you would recommend? COMODO's, or something else? It must suite my Avira's AntiVir as well.
Thanks a lot! 
P.S. also, is there something better / safer / more comprehensive/effective registry cleaner than COMODO's one?
Source(s):
http://www.kaspersky.com/news?id=207575720
http://system-cleaner.comodo.com/index.html
Avira's AntiVir is NOT the best.
NONE of them are 100% effective.
This is what I use and I don't have any problems:
Anti-Virus = AVG Free.
Spyware = Spybot Search and Destroy from Safer Networking.
Spyware Doctor is also very good and is free if you download it from the Google site (more > still more > packs).
For a firewall - I don't beleave in third party firewalls.
Windows XP and Vista both have built in firewalls and they work just fine. if you connect to the internet through a DSL/ADSL Modem/Router, you have a builtin hardware firewall. there is no need for an additional software firewall. if you disagree with me try Zone Alarm.
I suggest to use KasperSky Internet Security. its very best virus protection. I using KasperSky from 2 years and have no any problems with KasperSky. for more information >>>>>>>>> http://www.mdofpc.com/onlinestore/
FREE anti-virus, anti-spyware and firewall - best?