Posted 27 March 2009 - 10:58 AM
As BMartin has intimated, when you switch from a commercial to a free AV there is a lowing of expectations that you should be aware of. The companies that put out free versions of their AV's aren't doing it as a public service, they have commercial versions that they want to sell to you also so the free versions are intended to be enticements into purchasing their commercial version. That is why they leave out some features and give no or less support and many times ease of use is lacking in freeware.
When I was new to computers I had Norton installed. After learning a bit more about computers and security I switched over to Kaspersky. The main reason for that was that was that KAV doesn't badger you to pay for a major upgrade every year--all program upgrades are free--and their support is better than Norton's.
Then after using KAV for a few years and learning even more about computers and security, I've switched to AntiVir. I tried AVG 8 when it first came out and did have some experience with 7.5, but went back to AntiVir because of the same reasons cited by txtchr--and even if 8.5 makes all the bugs go away, I won't recommend them because of the attitude of their forum support people.
All this leading up to say that the first thing you will probably miss is a scheduler for running scans and a lack of a more complete control over your app. The main reason I settled on AntiVir is that it is capable of scheduling scans where AVAST and AVG 7.5 didn't. AVG 8 includes a scheduler for scans, but the definition updater was out of control on my systems.
You also get more control over the program with AntiVir. One feature in this regard I find essential and that the others don't have is the ability to exclude certain files and folders from scanning. This is needed because of false positives and near positives that are more common with free AV's and, unfortunately, AntiVir. But this is even more important because both AntiVir and AVG will scan and quarantine restore points in the SystemVolumeInformation folder, which is not a good practice because disturbing that folder will break System Restore at least temporarily. With AntiVir you can exclude that folder from being scanned and another option is to configure it to not remove/delete what it detects as malware or a possible risk. You can't do that with AVG 8 and Avast doesn't allow exceptions.
So if you know what false positives are and how to deal with them, and you have a decent knowledge of computers and security best practices, the latter of which means you don't often, if ever, get infected, then a free AV is a good choice. Either Avast or Antivir--I won't comment on Comodo and some others as they are too new and I have no experience with them. Especially if you don't often get infected, why pay for something that you hardly use. But a free AV will take some getting used to after you've had Norton installed.
BTW, most AV's now offer automatic updates and do so on a daily basis, unlike a few years ago.
The fate of all mankind, I see
Is in the hands of fools