Many people say that Linux system do not need any anti-virus software. But I also found many articles about virus on Linux. Now, many web pages are not safe. So, I want to find an antivirus software, or a firewall to protect my linux system. What I want is protect linux system, not just clean those virus for windows while they are in the linux system.

Pretty much any linux distro has a firewall installed. Google "iptables". For antivirus looks at ClamAV or AVG for linux. What sites are you looking at that say there are viruses for linux? The odds are very much against you getting an actual virus that these programs are designed to catch. The things to worry more about are social engineering exploits - ie, be careful what you allow to run, be careful where you put your personal info, be careful granting root privileges. For safer browsing, turn off cookies and javascript.

I had installed AVG twice, but I cannot find it the Applications or anywhere. I cannot launch it at all. About virus for linux, many website have some old articles, I just google "virus on linux"......

You should get a menu entry. Check /usr/share/applications and see if there is an entry for it. You should also be able to launch it by hitting "ALT+F2" to open a run dialogue and typing "avggui" (without quotes). Check the documentation: http://download.avg.com/filedir/doc/LINUX_GROUP/AVG_Free_for_Linux/avg_afl_uma_en_75_2.pdf [Modified by: Reed on May 12, 2009 12:13 PM]