How good are online AntiVirus and AntiSpyware programs?

AVG Antispyware, Bit Defender, SuperAntispyware, Computer Associates Security Advisor, etc.

How well do these online virus scanners and antispyware programs work? Are they updated with the most frequent virus definitions as regularly as they become available?

I'm just wondering if I should just stick to all of these online scanners (without installing any on my computer itself) and scan my computer fairly regularly with them. I don't download a ton of stuff that isn't from a legit place. I am very careful about what I download and make sure that it is what it is. I'm just wondering if anyone else out there keeps these programs off from their computer and just uses their internet equivalent?

I could understand the important of having them installed directly on your computer, particularly for those who don't know much about the internet; or who download all kinds of weird things from unknown sources on the internet.

Some things, such as Zone Alarm, I wouldn't mind keeping

How good are online AntiVirus and AntiSpyware programs?hijackthis

have used AVG for years - I never have any problems with it

How good are online AntiVirus and AntiSpyware programs?malware

then I have question for you, how many viruses, spyware, malware, pop-up every day. Updating weekly %26lt;usually automatic%26gt; Av/antispyware, malware software is essentials.