Some unlucky people may have noticed their computers behaving strangely. Frequent pop-up windows, a slow system or unreliable Internet connectivity may all be symptoms. The more of these symptoms you have, the greater the chances your computer is infected with adware or spyware. These programs (we'll just use the term "adware" for simplicity) have proliferated with frightening speed in the last year or so. Not so long ago, the important thing was to protect your PCs from virus attacks. Now there's a new bad guy in town. Adware can be "caught" easily, and isn't detected by antivirus software. Once it's on your machine, it's very difficult to remove.
Many moons ago (okay, call it 2003) there were a few free tools to remove adware. Those tools are still available, and most have been improving over time. However, the big boys like Symantec and McAfee have finally entered the ring. These 2 major antivirus software companies now provide a collection of programs designed to provide your PC with overall security. They'll block things like viruses, internet attacks, spam, adult websites, and yes: Adware.
In the past, I used to tell people they didn't need the "security suite" collection. Back then, all you needed was an antivirus program and maybe a firewall. However, times and the Internet have changed. More protection is needed. While it does mean more things on which to spend money, the price increase isn't much higher than just getting an antivirus program.
There are several tools (free and otherwise) for keeping your system clean, but there are a lot of options available. If you go online and search for "adware removal", take some time and browse through more than half a million results. This is a monster of a new industry, and it's moving fast. Due to adware's fast proliferation, companies are changing gears and shifting to new policies and programs. If it all seems frustrating and confusing, take comfort you're not alone. Give some time for the electrons to settle, and soon adware will have gone the way of the virus: It's annoying and possibly dangerous, but not a real problem when you have the correct software installed.