You should use Firefox as your browser. Besides those recommended below I use www.malwarebytes.org
Anti-spyware software Spyware and adware
are other big threats to computer
security. Spyware tracks your Web
surfing and reports your interests
to a computer on the Internet.
Adware sits on your computer and
feeds you ads. Both spyware and
adware will slow your machine.
You need programs
to keep spyware and adware from
taking root. And you need other
programs to annihilate spyware and
adware that collects on your
computer. You should use multiple
anti-spyware programs on your
computer. Unlike antivirus software
and firewalls, they won't conflict.
Free anti-spyware
programs:
•
Ad-Aware •
Spybot Search & Destroy •
Microsoft Windows Defender •
SpywareBlaster
http://www.komando.com/securitycenter/