General Info
Spyware is often used as a general term to encompass Adware, Spyware, and Malware. To correctly identify each, the definitions are listed below:
Adware (Advertising Software) is a software application in which advertisements are displayed while the program is running, esp. in pop-up windows or banners, and which often is installed without the user's knowledge or consent.
Spyware (Spying Software) is any software that covertly gathers information about a user while he/she navigates the Internet and transmits the information to an individual or company that uses it for marketing or other purposes.
Malware (Malicious Software) is software, such as viruses, intended to damage or disable a computer system. Malware often work in conjunction with Adware.
Spyware Removal
The first step in getting rid of spyware is to uninstall any programs you did not intentionally install through the Add/Remove Programs found in the Control Panel.
There are a number of Anti-Spyware programs that you can purchase to remove spyware from your computer. Here are a few effective FREE tools:
Ad-Aware Personal provides advanced protection from known data-mining, aggressive advertising, Trojans, dialers, malware, browser hijackers, and tracking components. Please be aware the free version of this software is for home users only. Departments must purchase licensed copies for distribution.
Windows Defender is a security technology that helps protect Windows users from spyware and other potentially unwanted software. Known spyware on your PC can be detected and removed. This helps reduce negative effects caused by spyware including slow PC performance, annoying pop-up ads, unwanted changes to Internet settings, and unauthorized use of your private information.
Spybot - Search & Destroy can detect and remove spyware of different kinds from your computer. Spyware is a relatively new kind of threat that common anti-virus applications do not yet cover. If you see new toolbars in your Internet Explorer that you didn't intentionally install, if your browser crashes, or if you browser start page has changed without your knowing, you most probably have spyware. But even if you don't see anything, you may be infected, because more and more spyware is emerging that is silently tracking your surfing behavior to create a marketing profile of you that will be sold to advertisement companies.
Lastly, a good resource for determining the validity of a file is http://www.sysinfo.org/.