Here is a list of the recommended anti-spyware software.
Note that the installation of anti-spyware software is not mandatory and does not necessarily improve the protection of your PC and most Antivirus programs can handle the detection of spywares.
Malwarebytes' Anti-Malware from Marcin Kleczynski and Bruce Harriss
Currently considered as the most effective tool for removing spywares and malwares
The free version has no real-time protection, and must be manually updated. Download Link Official website
SUPERAntispyware from SUPERAntiSpywareom
An effective tool for disinfection.
It has a "Hijack Protection" which, provides protection against piracy (hijacking the homepage, search pages from the net).
The free version has no real-time protection, and must be manually updated. Download Link Official website
A-Squared, from Emsi Software
A-Squared (Emsisoft Anti-Malware) is an anti-trojan tool that can remove many infections.
The free version has no real-time protection, and must be manually updated. Download Link Official website
Spybot Search and Destroy by Patrick M. Kolla
An effective antispyware that can "vaccinate" the most popular browsers in order prevent infection.
It has a real-time analysis via the Tea timer feature, which can monitor changes made to the registry.
The update is manual. Download Link website
Windows Defender, from Microsoft
This software is not the most effective one but has the merit of being free, simple to use and providing realtime updates, and realtime protection.
SpywareGuard by Javacool
This software can perform a real-time analysis without slowing down your PC. It also prevent the redirection of your homepage.
It works via a heuristic analysis.
The update is manual (but non-existent since 2004!). Download Link website
Spyware Terminator, by Crawler LLC
It prevents spyware, adware and keyloggers from attacking your system.
It offers real time protection to prevent unauthorized programs from accesing your PC.
Spyware Terminator can operate in the background.
Note that:
During installation, uncheck the box next to "Web Security Guard", which is a toolbar harmful. Download Website
The Cleaner, by Moosoft Development Inc
A program that can remove many infections.
In the free version, updates are manual. Download website
SpywareBlaster, by Javacool
This program allows you to immunize Firefox and Internet Explorer against known spyware.
It does not provide any analysis tool. The updated manual is in its free version. Download Webite
IObit Malware Fighter
Download
Website
IObit Malware Fighter (the successor of IObit Security 360) is a software which can help to protect your computer against spywares, trojans and other malware . It automatically detects and removes threats on your PC before they infect your machine. This software is completely free, and is compatible with Windows Vista, 2000, XP and 2003.
How to choose the right anti-spyware software?
Installing SpywareBlaster will immunize your browsers (Firefox, Opera, Internet Explorer) without slowing down your PC.