Hey, thanks for coming. This is my hosts file. For those of you who don't know what a hosts file is, read along; for those of you that do, feel free to skip ahead to the negatigerbar.
A DNS server is a Domain Name Server. It translates the address that you type into your address bar (like 'www.cnn.com') from the words that you understand but the computer doesn't, into the numbers that the computer does understand. Your ISP has one or more computers that does pretty much nothing but this for you. It's a gymungus list of all the domains in the 'Net, and is updated every so often so they're all current. It's kind of like the phone company's big ol' yellow pages.
A hosts file is like your little black book. You put the domain names and IP addresses into the hosts file, and your computer will look there, before it talks to the DNS server. This isn't an enormous amount of use for normal people, but you can take advantage of this behavior to kill off some of the more obnoxious ads, like the flashing and jittering 'you may have won something and all you have to do is spend ten times what it's worth and give us permission to spam you bowlegged!' type ads. This also helps prevent tracking cookies, although it doesn't cut them out entirely, (I'm working on that) and it isn't a replacement for a real anti-spyware program, or preferably at least two, like Ad-aware and Spybot Search and Destroy. But it is a supplement, like taking vitamin C when you have a cold. It doesn't fix things on its own, but it can help out the more powerful things you're taking too.
What you do is download this file by rightclicking and choosing 'save target as' (In IE. In other browsers, your mileage may vary; you are assumed to be intelligent enough to operate it.) and saving it on your Windows Desktop. (This may work in other OS's; I dunno. I dun-care, either.) You can open the file in Notepad, it's a plain text document. Once you've satisfied yourself that I'm not trying to give you a trojan or something, rename the file by rightclicking it and choosing 'rename', and name it hosts. Notice the lack of a period and exe or txt or anything. This is important. Once you've renamed it, copy or move it into c:\windows\ (Win95, 98 or ME) or C:\winnt (2k and XP). It may ask if you want to replace a file that's already there. If it does, you're best off checking what that file that's in there is. Easiest way is to hit cancel on the message, then rightclick the desktop, choose new then shortcut, and when it asks for the command line, type: C:\WINDOWS\NOTEPAD.EXE "c:\windows\hosts" exactly as it shows in bold. Then hit next, give it a name something like 'Hosts File' or whatever is meaningful to you, and hit finish. Then doubleclick that icon. If what you see in there all has semicolons (;) in front of it, all is cool; it's a sample file and doesn't mean anything. Go ahead and replace it. The semicolon makes the system ignore anything after it, so you can put notes in.
If there is anything in there that looks like 123.456.789.012 example.com, then it means for some reason you have hosts entries already. (Note: that is a phony IP address. Real ones won't be any higher than 255.) If you recognize it, good. You may want to copy/paste the contents of my file in there, too. The file must end with a blank line; after the final entry, hit enter once, then save it.
If, as once happened to me, you don't recognize them, you may have inadvertently installed a program at some point that modified your hosts file. About 2/3rds of the entries in my file came from a spyware program that plunked the addresses for about 200 pr0n sites and their IPs into my hosts file, to get around just such a thing as I am doing here.
Made it really easy to pre-kill a bunch of them. Just change the IP address to 127.0.0.1 and there you go. 127.0.0.1 is the loopback address, usually used for testing on a computer. In this case what it does is point the browser to Nowhereland. You get a broken page error, like you'd typed in aowd[ighaw[otginhwergoiwnhgqsrd.com. This means, that if it's a pr0n site, it comes up a blank page saying 'Page can't be displayed', you can close it and it goes away, instead of opening another 69,105 other subpages, that themselves each open another 69,105 subpages when you try and close them, and so on, and so on.
(As an example, while I'd cleared out my hosts file and was looking for a good site to use as an example of with/without ads, a bunch of popups came up and hung my system.)
Ok, you can come back now...
On this page, you can see two examples of one website, with and without the hosts file active.
If anyone knows how to get a flash ad to give up where it's coming from, please tell me? Some of the more obnoxious ads are the flash animated crap. I know how to look in the source, but sometimes that doesn't work.