
Many programmers and some commercial firms have released products designed to remove or block spyware. Here's the free software to block Spyware for your PC.
1. Ad-Aware 2008 (free scans for non-commercial users)
Ad-Aware 2008 Free is Lavasoft's freeware
anti-spyware software that is available for home, non-commercial use. It is offered to consumers worldwide to protect their personal and home computers from malware attacks, and has been downloaded over 300 million times worldwide. The download includes skins, help manuals and the latest definition files, however, real-time protection and
anti-virus protection are not included with this version. Real-time protection and other advanced features are available in the paid versions of Ad-Aware 2008.
Spybot - Search & Destroy (often Spybot-S&D) is a popular
malware, spyware and adware removal program. Like most malware scanners, Spybot-S&D scans the computer
hard disk and/or RAM for malicious software.

Windows Defender not only features system scan capabilities similar to other free products on the market, but also includes a number of real-time security agents that monitor several common areas of Windows for changes which may be caused by spyware.
GIANT AntiSpyware was a spyware detection and removal application developed by GIANT Company Software, Inc.