how-to block ads
Banner ads are re-directs. They can be from an external site to where you are visiting. In this case they are controlled by doing something with the IP address that the ad is coming from. The tougher ones are the ads from an area of the web site itself, since you are in the site and have their html code bypassing your screening.
I don't know the details on a lot of the programs that are out there, but I have learned enough about how the sites work to control a lot of what goes on.
There are ways to do things without programs, obviously any program is only going to be a pre-built system to do something for you. Some in a more elegant way than others.
The two main lines of defense involve controlling the IPs and controlling the commands. While this statement may seem like the same thing, it is 2 separate approaches to the problem.
I think an explanation of hosts file may be helpful.
When you go to any site, you need the numeric address for that site to get there, not the typed words. Think of a phone book- you call John Smiith by finding a set of numbers to reach him. Your computer goes on the net to a DNS server with the words and finds the numbers, then when you have the numbers, you can reach the site.
In the early days of internet when it was really slow, you could create an internal "phone-book" for the sites you went to often, and your computer would look in the hosts file first to see if you (had) could get a numeric address a lot quicker. With the increased speed, this became a moot point.
But then it was discovered that you could make a list of deliberate wrong numbers for some sites and your computer could never go there. The "wrong" numbers used were dead end loops back into your system itself. ( 0.0.0.0, 0.0.0.1, 127.0.0.0, 127.0.0.1 ). So adding a site like doubleclick in the hosts file with a wrong IP address effectively stopped the computer from ever reaching the site, since your computer finds the numeric address on your system first before trying the DNS server.
So a lot of ads are controlled by using some form of a list.
One problem is that there are sites that you want to OR have to go to, so a second way of controlling things is needed. This involves the different zones of IE and what is allowed in the zone. Restricted is the workhorse here. It is set to not allow downloads, not allow scripts... and the "bad" sites are added to the restricted zone to control them. In short, you can go to the site, but you don't allow much of anything to take place there.
When you are on a site with the annoying flashing changing banner, you right click on the banner, choose properties and look to see where the banner is coming from. If the address is different from the web site, it can be stopped. If the address is a layer of the site itself, then it is a lot tougher and may have to be lived with without some major jumping through hoops to stop it.
Other sections of this FAQ area will deal with specifics of some pop-up blockers which can be anywhere from simple 'don't allow another window to open' to 'check this list first and see if the site is on the No-No list' to an elaborate set of customizations and rules to control just about everything.