Well anti virus softwares are a must have especially if u download . I have tried many of them personally and i give these softwares the top three ranks. All these softwares have been personally tested by me and with unbiased ratings :
RANK 1:
NORTON ANTIVIRUS 2007:
No prize for guessing this antivirus software is the best I have used , it has regular updates , cleans well and gives vista like security. The main reason I recommend this software is that it is very user friendly and even a noob can use it.
This software removes trojans , spyware , adware ... name it - it does it. It has great customer care and has vista like 3D display. This software also checks for windows updates , so beware pirated XP users. If your are using a pirated copy I recommend you turn windows updates off on norton (right click > change notifications >and untick the options.) I recommend you update this software every week and have a full system scan every week too.try the demo http://www.symantec.com/.
RANK 2:
AVAST!
CNETs highest rated antivirus . This software is really good and the one thing special about it is that when it detects a virus it cleans it at start up so its safer to clean . Its as good as norton and a bit faster to ,but... its not that up to date with virus definitions and stuff .But none the less its an excellent software and doesn't take up much CPU usage .Download it from http://avast.com/
and best part is you can download the full version of avast! home edition with the keygen legally . so what you waiting for ? yes you heard it right you can download the full version with keygen legally at www.avast.com , yup this one is the "BEST FREE ANTI VIRUS"
RANK 3:
ZONE ALARM
This is an awesome software , it can clear any virus , block any hacker , preventing anything that has the slightest chance of spoiling your computer . Its very good if you have a lot of malware and it is definitely up to date . ''what is wrong with this software you ask?'' its NOT user friendly . Its definitely not for noobs , its complicated and I couldn't even got on IRC when I installed this software , It took some time before i could pass thought it. Its excellent much better than norton and has definitely earned its ratings but its not user friendly and wouldn't recommend it for amateurs . You can download it here http://www.zonealarm.com/
P.S: I haven't tried AVG antivirus and wouldn't recommend mcafee
Top anti-virus softwares ... a must have
