You should register as a pre-teen (under 13) because the website is then prohibited from doing different things to your system (I think tracking cookies and the like).
The head of our I.S. Department at work introduced me to the spy-ware killer, Ad-aware 6. It comes in two flavors: the "Professional" version you have to pay for and the Standard version with less bells and whistles that you can download for free. It runs a C-Drive scan whenever you chose to do so, isolates all spyware and then asks if you want to quarantine them or delete them.
You can download it for free from Lavasoft. Follow the links to the regular version down-load page.