The way to protect yourself and AntiVirus tool

In the information era of current world, most of time is spent with the computer and network, it speeds up the work effeciency or the computer and network is just becoming the necessary part of our daily life. We use the computer to draw a work plan, debug a program, design a vehicle and much more. In the spare time, we also watch tv, vedio using the computer, do on-line shopping and so on.

Someday, you just accidently open an email from one of friend(hijacketed),or open a webpage ,or download a program. now the scenario has to changed, your computer is becoming slower and slower, and automatically reboot itself, black or blue screen...now, you can not access the the files in the computer, you can not do anything with the computer until you can recover the computer to the previous stage. Worse, the antivirus has stolen your private information such as your bank card number if you used your computer to go to the online bank. This information has been recorded by the spyware without your notice at all before.
Anti-virus software generally has two ways to detect the virus, one is to use the dictionary, another is to check the suspicious behavior(heruistic scanning). Once it found the infected files, the anti-virus software will try to delete or quarantine the file.

The procedure antivirus software work:
The protection by Norton

"If only the virusdictionary is used, it is important to update it at least once a day. When you bear in mind that 15 new viruses are discovered everyday, an antivirus that is left for two or three days without being updated is a serious danger"(http://www.net-security.org/article.php?id=485&p=3)

The heuristic scanning method may(in rare cases) prevent some normal software working, the user should be aware that case and do the corresponding way to solve that conflict. The related news on the web:"Mark Griffiths of Brisbane said he is "not ruling out" filing a lawsuit against McAfee even after the antivirus company released on Thursday an update to its DAT virus definition file that fixes the false positive." http://news.com.com/2100-7350_3-5361660.html

In order to reduce the your risk as possible to lost the files you want to keep.
1.Install the respectable anti-virus software and update it frequently.
2. When it is necssary, to set up a windows restore point,you when the system crashed, you can go back to that point.
3. Update windows(if you use the windows system)