Pareto Logic - XoftSpySE
Get your free download of this software, which removes spyware, adware and popup generators, and cleans your Windows registry. Their free scanner will check your system and let you know if your computer is infected. "XoftSpySE detects and then removes over 43,000 harmful, dangerous and unwanted applications. Detections include Adware, Spyware, Trojans, Worms, hijackers, toolbars, Keyloggers and many viruses."
Get your free scanner here

NoAdware
Also offers a free scan of your computer, to check if your computer is infected with spyware or adware. Their full system offers options to protect your computer from future infection.
Check all the features and get your free download here.

Adware Alert
Scans your computer for Adware and Spyware, and removes them. Block pop-ups. Prevents your computer being infected again. Has online updates which cover the latest spyware threats.
Also offers a free system scan.

Spyware Nuker
Gets rid of the Spyware on your computer, which may have been installed without your knowledge after you downloaded free music, games or screensavers from the web.

You can download it and try their free scan.