Spybot - Search & Destroy detects and removes spyware, a
relatively new kind of threat not yet covered by common anti-virus
applications. Spyware silently tracks your surfing behaviour to create a
marketing profile for you that is transmitted without your knowledge to the
compilers and sold to advertising companies.
If you see new toolbar in your Internet Explorer that you
haven't intentionally installed, if your browser crashes inexplicably, or if
your home page has been "hijacked" (or changed without your
knowledge), your computer is most probably infected with spyware. Even if you
don't see the symptoms, your computer may be infected, because more and more
spyware is emerging. Spybot-S&D is free, so there's no harm giving it a try
to see if something has invaded your computer. Spybot-S&D can also clean
usage tracks, an interesting function if you share your computer with other
users and don't want them to see what you have been working on. And for
professional users, Spybot-S&D allows you to fix some registry
inconsistencies and extended reports.It can be downloaded from here