What exactly do they do?
It depends on what kind you have. Some can send information to the makers, some can log your keystrokes and send the info to the makers (this would include passwords, credit card numbers, etc.), some can change/disable your settings, some can hog up your bandwidth and slow down your connection, some can even dial out with your line and possibly make charges to your phone, and some can open up a "backdoor" and allow all of these other types of infections to sneak in without your knowledge. The list goes on. None of these actually damage your computer, but I would hardly call them harmless.
I have seen many people rave about how good AVG is, so I was just gonna assume that they were okay to leave there. Is it probably unwise to just ignore them? Because they show no signs of being in action on my computer.
They might be perfectly safe, but if I were you, I wouldn't take my chances. 'Tis better to err on the side of caution.
If you only go to 'safe' sites and don't download anything from emails, wouldn't Norton be okay? I don't go to 'unsafe' sites.
I would suggest downloading
Spyware Blaster and
SiteAdvisor to help ensure that the sites you visit really are safe.
I was going to keep Norton for my firewall and scan with it now and then. I was also going to keep AVG, but just not have it running all the time. I'll just do a scan with it weekly. Would that be an okay setup?
I still stand by Norton being a bit less than desirable, but if you keep AVG as a backup and remember to update it and scan regularly, then I imagine you'll be alright. When you scan those files, post the results here for us to take a look at.
I did another scan with Kaspersky and saved a log. Should I post it here, or do it elsewhere?
But something about this scan was very odd. On the last scan, it detected 4 virses and 7 infected files. This time around there were only 2 viruses, and 16 infected ones. I think the infected ones are harmless, because they are in the system restore folder. Or I could be wrong....
Go ahead and post your log here for us look at. Also, when you scan, it is often advised to turn System Restore off. This will delete your restore points. You'll want to do that because if you ever need to restore to an older point, those infections will be put back on your computer. After scanning and getting a clean bill of health, you'll want to turn System Restore back on and create a new restore point.
Also, is it wise to let Norton remain as my firewall, but do a lot of my main scans with AVG (which isn't running constantly)?
Running Norton Firewall shouldn't give you any problems. But when you scan with AVG, Norton Antivirus should be temporarily disabled.