The first thing is to remove the adware and spyware that has already infected your computer. There are many programs out there claiming to get rid of spyware. Most of these programs actually just install more of it. Fortunately, there are a few programs out there that are for real. The better news is that the two best anti-adware programs I know of are free.
Spybot Search & Destroy
The first program is called Spybot Search and Destroy. The project was started by one gentleman with a special interest in privacy. It has since grown into what many consider the most effective anti-spyware/anti-adware program available. A small group maintains the program and distributes it on their web site for free. They do ask for a nominal donation from the bottom of your heart, but it isn't required.
Spybot's focus is on accuracy. The program aims to remove all the spyware that it can find on your computer without any false positives. A false positive is when an anti-adware program identifies a legitimate file as spyware when it shouldn't. False positives are a pet-peeve of the Spybot team, and they work very hard to avoid them. You can be certain that when Spybot identifies a file, it really is a malicious file.
The program is easy to install, easy to use, easy to update, and most importantly, its effective. It eliminates the adware currently on your system and blocks it from coming back. The newest version also offers real-time protection by blocking adware programs as they try to install themselves, warning you if anything acts out of turn. You can download Spybot from my downloads page.
After you download the file, double click it to install it. The installation is straight forward. The first time you run the program, it should ask you to update the program and make some back-ups. Just follow the directions it provides. You only have to do that once.
From then on, try to run the program about once a week. Every time you run it, get all the available updates first (through the "search for updates" feature inside the program.) Then, use the immunize feature, which blocks known bad programs. Finally, run a scan. That should keep your computer free of all adware and spyware.
As good as Spybot S&D is, it’s a big internet out there. In order to keep all your bases covered, you should install a secondary program. I recommend Adaware SE Personal by Lavasoft. Also easy to install, update, and run, Adaware will easily mop up anything that Spybot doesn't cover.
Adaware's focus is on completeness. Lavasoft really wants to get all the adware and spyware off your computer, and they use very aggressive scanning to get the job done. They feel that your privacy is worth a few false positives. The result is a very through scan of your computer. Just make sure you look the list of files it identifies over for false positives or you may loose access to a file you actually wanted.
Remember to keep both programs up to date and run them regularly.
im a computer technition