HISSIN50 said:
Danny, I never understood why running two AV programs simultaneously was supposed to be bad - I used to do it and neither seemed to get in the others' way.
On-Access Scanners
"Can I run two virus scanners at the same time?"
There are two types of anti-virus programs. Those that you invoke explicitly (called on-demand scanners) and those that are always active in the background (called on-access scanners).
You should never let two on-access scanners monitor your system at the same time. Instead of providing better protection, the combination of two or more such scanners will likely cause your system to behave in a weird manner and possibly crash because the scanners will interfere with each other.
Also, a single background scanner will use some of the resources of your computer; the supplementary protection offered by the second scanner is not worth the additional resources it consumes (and the additional trouble mentioned above).
However, you can install as many on-demand scanners as you wish. Because they do not run simultaneously, they won't disturb each other, and two scanners detect more viruses than one. Note that you should switch off your on-access scanner before running an on-demand scanner.
On-Access Scanners (sometimes called Memory Resident Scanners), as their name implies, run in the background all the time the PC is switched on and running. Usually you will see a little icon in the taskbar that indicates it's there. The main function of an on-access scanner is to monitor all activity on your machine, like files being read, processor streams, Internet downloads, receiving, sending and reading email and so on.
Basically they watch what's going on, and if they see something that they think is a virus, they tell you about it.
If you work in a reasonably large company, you may find that it is corporate policy to have a virus scanner running at all times on your workstation. That will be an on access scanner. They need updating just like all scanners, though they can usually be configured to make this automatic if you have a network or Internet connection.
"So, they're a great idea then, better make sure I get one of those!"
Well, yes, they can be a good idea, but let's have a think about it before we rush out and grab a copy of Poopscooper off the store shelf.
Having anything running in the background monitoring every file that is read, and every process in your machine, is very likely to slow it down somewhat. You might find that some scanners are better at crippling your machine than others, but when it comes down to it, it will have at least some effect. If you are constantly working on the Internet, using email, participating in chatrooms (IRC) or newsgroups, then it might be an idea to have an on access scanner running. However, if you are a strict practitioner of safe hex, don't really use the Internet much, use a sensible email reader that isn't going to let any old piece of code run, then you may find you don't need it all the time.
http://www.claymania.com/virus-specific.html
