Is there a more low memory and cpu consumer firewall and anti-virus for a Desktop?

I'm currently using AntiVir Free Edition as Anti-Virus and ZoneAlarm for my firewall.What version of Windows are you running?

I'm a technician of a computer cafe.
The OS is WindowsXP Home and WindowsXP Profressional Service Pack 2I'd RECOMMEND avast! for your anti-virus SCANNER.

It's served me WELL for years; it's free, quiet, slim, efficient, smart, and doesn't try to hijack your computer (which is more than I can say about Norton and McCaffee).What are the specs of those computers? Neither of the mentioned security programs is a big RAM eater.Considering the RAM of all of them is a 512MB
With a processor of 1.5-3.0GHz.

But in terms of specifications of both firewall and AV.
I only need about a 50MB RAM and 50KHz CPU Consumption for the games and applications run smoothly.I'm afraid, it won't happen.
Judging from my Task Manager, Avast uses ~110MB of RAM, for instance.
You can't expect smooth GAMING from the computer with 512MB of RAM.
Your best bet is to invest $15-$20 per computer, and add an extra 512MB of RAM.Thanks for the hint.
By the way.

Is there a lot comparison between AntiVir Free and Avast Free?What do you mean by "comparison"?Difference between the TWO in terms of performance and RAM&CPU ConsumptionI just checked Avira on my XP, and it looks like it's less RAM hungry - below 15MB.
As for the performance, both are excellent programs.OH. Thanks for that.
How about any firewall.

In my personal notebook.
I use KIS 2009.

But I want my computers to have the same kind of security both features of AV and IS Scanners.

I've used ZoneAlarm but I'm not yet satisfied by its features.
There are still threats or security breaches that infects my computers.

I need this info to lessen the number of repairs in my computers and also to increase it's security in a stealth manner.- free PC Tools Firewall Plus: http://www.pctools.com/firewall/

- free Comodo Internet Security (firewall + AV): http://www.personalfirewall.comodo.com/ (you can install either a whole suite, or just a firewall)

Since this is internet cafe, you really don't need two way protection, so Windows firewall will do, as well.