Advertising Supported software (adware) is the most common; however some programs (spyware) will spy on your activities as well for market research. Adware is a way for shareware authors to make money from a product, other than by selling it to the users. There are several large media companies Web3000, EverAd, and Aureate, just to name a few, that offer to place banner ads in their products in exchange for a portion of the revenue from banner sales. This way, you don't have to pay for the software and the developers are still getting paid. If you find the banners annoying, there is usually an option to remove them, by paying the regular licensing fee.
Well one might not be offended if all they are doing is trying to get to know you. But this turns into an obsessive, annoying advertising when every time you visit a website an advertisement pops up, you get funny icons on your desktop without you putting them there etc. Working on your computer peacefully becomes pretty much impossible and your computer is slowing down from minute to minute making usual tasks impossible to execute.
If you think you have been infected by an adware or a spyware there are always adwares and spywares removal tool available on the internet. Websites are filled with anti-spyware/adware softwares, online scanners and removal tools to get rid of these annoying banners or pop-ups. These softwares, removal tools or online scanners search your registry, local hard drives and system files to detect these adwares and then get rid of them by either deleting them, quarantine or repairing the file. But you should be careful as many of the softwares that say are a removal tool but really they are another Trojan, adware, spyware etc that will get your computer infected.
The best thing to stay safe while browsing over the internet is to have an adware/spyware removal tool installed in your PC. To run that removal tool on a daily basis as one click can infect your PC in no time. If you don’t own a software than at least make sure you run a full scan online from time to time. It will surprise you how many adwares can infect your computer in a small number of time.
Free adwares and spywares removal tool can be found on the following website:
http://www.bitdefender.com/site/Download/browseFreeRemovalTool/
www.symantec.com