Security Software

Microsoft Security Essentials is a free and easy to use Anti-virus and Malware scanner that does a good job in detecting a variety of malicious software.	Get It Here
ThreatFire is a free zero-day scanner that looks for malicious or suspicious activity to help reduce the spread of new, undiscovered malware.	Get It Here
Spybot Search & Destroy is a free spyware scanner that does a good job detecting issues. Installed without its TeaTimer saves valuable resources, but requires you to perform manual scans.	Get It Here
Malwarebytes Anti-malware is a free malware scanner that can complement your other security software. The free version doesn't include an active scanner, so manual scans are necessary	Get It Here
Lavasoft AdAware is a good ad-ware scanner. It is able to detect and remove malware that affects the default ads on websites and creates annoying pop-ups	Get It Here