Client Antivirus is a niche of antivirus software that serves as an all encompassing guardian for a server, protecting any and all clients that might be on that server. At first glance, you might assume that this is the same realm as regular antivirus software but the business world is far more cutthroat, even when it comes to viruses. Whereas one antivirus program might protect one computer, a Client AV program must protect several or even dozens of clients using that particular server. As such, only the best AV clients are worth mentioning. On that note, here are three fantastic programs, all worthy of being called the best AV client 2011 has to offer.
ESET NOD32 Antivirus 4
This software is made by the very respectable Kaspersky company. Kaspersky has been providing us with quality antivirus products for years now but they may have topped themselves this year. ESET NOD32 is very good at seeking out new threats even before they come up, zapping away dangerous programs and files long before they have the chance to damage you. The best part, though, is that the program is very good at using limited resources. This means that doing a scan won't slow your computer down to a crawl, a must for any serious antivirus client.
Avast has long been known as a wonderful antivirus provider for regular consumers but their new Pro version is simply one of the best community security products ever made. Avast Pro protects your network against not only viruses but also spyware of any kind. Their support staff is also second to none, providing endless help and information whenever they're needed. The live updates are also incredible and go a long way toward making sure that you're protected from viruses no matter how new or powerful they might be.
Spyware Doctor with Antivirus 2011
Spyware Doctor has been getting major buzz this year because, put simply, its 2011 version is simply fantastic at rooting out and removing viruses, adware, and spyware. Few programs are as comprehensive as Spyware Doctor and even fewer are as good at blocking and removing viruses the way that Spyware Doctor can. The 30 day money back guarantee is also a nice perk, and it helps us know that Spyware Doctor is very confident in its abilities. Most importantly, the program is a breeze to install and updates automatically, making it one of the most user-friendly AV clients around.

Kaspersky Antivirus 2011: Kaspersky Antivirus 2011 hits the #2 spot. This antivirus software simply works. While the cost is higher than most, you get what you pay for with Kaspersky Antivirus 2011
ESET NOD32 Antivirus 4: ESET is quickly becoming a favorite antivirus client among many experts in the virus removal field. This client has potential to take over the #1 or #2 spot
Thanks. I used to stick with Eset Nod before but now i switch to Vipre Antivirus because of its performance.
the best i have seen is norton anti-virus……but it takes much of the computers performance(if u are using a high processor ,ram etc then it is good 4 u), eset antivirus is good