Spyware&Adware comes mainly from 2 sources: Internet websites that use Internet Explorer exploits to enter your computer and free software such as: Almost all P2P filesharing software(Kazaa, Morpheuos, etc...)[there are a few exceptions such as Shareaza]. If software is free and the website you get it from looks to be well paid
then you should suspect that it installs spyware/adware on your computer.
What spyware and adware do:
Spyware sits on your computer and comes up everytime you boot your computer. It monitors your activity and reports this data back to "home". "home" is whomever created the spyware. This person or people or company then sells the data for cold, hard cash. A portion of the cash is given to the websites/companies that participate in their "program".
Adware also sits on your computer. Adware in its purest form only forces pop-ups to come up on your computer. Since these ads are software driven pop-up blockers can do nothing to stop them and you don't have to be visiting a website to have them come up. The money made from showing these ads go to the makers of the adware and they give a portion to the websites/companies that participate in their "program".
A program can be one of these, or it can be both. Poping up ads _and_ stealing your surfing habits/etc...
How to prevent:
Norton has various software selections. I don't know the exact software bundle, but there is a couple peices of software that when kept up-to-date will protect your computer from expliots. This doesn't stop software that you willingly install yourself, but it covers one hole. As for software you install yourself that also includes spyware: Download&install smart, don't blindly do things. If you are suspicious of a peice of software take the time to read it's end-user agreements. The agreement _must_ point out that this software has the right to monitor your activites, etc... Hopefully you can get through the endless attorney jargon in those documents :-/
Keep Internet Explorer and Windows up-to-date by going to the windows update website and updating your computer. This is a fairly easy process. Do it every so often, say...every 2 weeks at least, but every week is better.
Finally, if you aren't too attached to Internet Explorer you could always try Mozilla or Mozilla Firefox. These are free alternatives to Internet explorer. No, they aren't "bad" free, they are very good and well constructed. And, if I recall correctly, they are open source. If you aren't familiar with that term, don't worry about it. It is usually synonmous with Good and Free. To get these web browsers visit: www*mozilla*org ___replace * with . the forums won't let me post a url yet :-/
Mozilla/Firefox is a much more secure application than Internet Explorer. You'll find that some website do look different under Mozilla, but that is only going to be because those websites developed for IE only and IE is not up to the web-coding-standards and since Mozilla is, poorly coded websites will fail. Don't worry though, if a website becomes unusable(rare) you can always switch to IE for a minute while you surf that site.
Mozilla is a full package of internet applications including an email client, web browser, and IRC client. Firefox is just a web-browser. If all you want is a web browser, then get Firefox.
Sorry for the long, long, long post, but I hope this information will help you and others to avoid the nasty money grubbing spyware/adware/other nasties(viruses and trojans) out on the internet.
