Internet Security!?

I am using Avira Anti-Virus Personal Edition (free edition) , Zone Alarm , Spybot -Search %26 Destroy, and Windows Defender. Avira im using to get rid of viruses, Zone alarm for a firewall, and spybot and windows defender for spyware. I am currently running on windows xp. If i use all these programs to protect my computer will it slow down my computer? are these programs good enough to protect my computer? and lastly, what are the best combinations of internet security that i should use?

Internet Security!?norton 360

That is a fairly good setup. Avira AntiVir is very good indeed and I use this myself, although I am currently using a 3 month trial of the Premium version.

Stick with Avira, it is very light on resources.

ZoneAlarm - I found this has become bloated recently, and the free version is not performing too good in recent firewall tests.

It scored "Very poor" in the Matousec leak test; http://www.matousec.com/projects/windows...

Good alternatives to ZoneAlarm, that offer better protection but use less resources are Comodo firewall or Online Armor free firewall -- both are free and very effective. I found Online Armor easier to use and it had less popups, etc.

http://www.personalfirewall.comodo.com/

http://www.tallemu.com/online_armor_free...

I'm not sure if there is much point in running 2 real-time antispyware scanners. I would uninstall Windows Defender personally and use Spybot S%26D for real-time protection, then just install 2 on-demand scanners that don't run 24/7.