11 Great Free Security Programs

[Hard_ROCKER]

Is there any way (besides the mess with service names, etc.) to use Avira as a second, non-resident, scanner?

Ups i didn't notice your post till now, sorry !
Tech i haven't tried that because i firmly believe in not trying to mess with 2 AV's at the same time, i got burned in the past once(thank god i did a system drive backup before) and will not go that road again. 
However i am running both XP and Vista on this machine and i have avast! on my xp installation and avira on my vista installation so i can scan my partitions with both AV's.

[Lisandro]

However i am running both XP and Vista

I have XP and Kubuntu.
I have avast on both... maybe I can consider to research for Avira in Linux (I'm not sure they have a version (free) for Linux).

[gdiloren]

I actually put on one WinXPSP2 computer AVIRA PE Classic as resident (for detection), BitDefender 8Free (on demand) and clamwin FREE or "turtleWin" as I like to call it (on demand and for the email plugin in Outlook (supposed to scan infected email but- and it's unclear-after emails are in your pc)). Should they conflict if I use the on demand scanners only after having deactivated the resident in Avira, one at a time? I don't know how long I'm gone keep that configuration...!!! Web pages have been created recently that put forward Avira and Kasperky as better detection than Avast and they're generally saying that Avast is on a downhill trend  .
I just talked to a colleague and she says that if you catch something that the other AV don't see and use the quarantine, it's ok;but, if there are two AV that detect the same virus or malware in the quarantine of the other, there's gone be conflict and your system could freeze and eventually be damaged. So quite frankly, is it just a matter of leaving the resident or not...

[Lisandro]

If there are two AV that detect the same virus or malware in the quarantine of the other, there's gone be conflict and your system could freeze and eventually be damaged.

A good program, with a good Quarantine, encrypts its content and avoid detection by other security programs.

[gdiloren]

Thanks, then I'll give that configuration a trial but I already miss Avast's features on that PC though!!