If you want to get the best from your PC, you don’t want to have adware or spyware running on it. Many antivirus packages (for example, Norton AntiVirus 2007, McAfee VirusScan or ZoneAlarm) can detect and remove certain adware and spyware, but it’s best to have a separate program to look for and remove these unwanted PC pests.
A number of free applications are available for you to choose from. One is called Windows Defender and is available from Microsoft. Another good program to install and scan with on a regular basis is called Ad-Aware by Lavasoft. You can install both of these on your system, having Windows Defender running all the time and using the latest Ad-Aware to scan your system daily (if you are security conscious) or weekly to check for and remove anything that might have managed to sneak by Windows Defender.
Be sure to check out Download.com’s selection of adware and spyware applications.