I like spybot, but be careful about the hosts file additions it makes
for you in the advanced menu. I added these, and then found that I
couldn't reconnect to the internet, and when I rebooted that my system
ran impossibly slow (eg. it took 20 minutes to shutdown). I brought up
the system in Safemode, brought up Spybot, reversed all the
quarantined spyware that it found, and I still had the problem. Then I
changed the hosts file back to what it was and everything was fine
again. I got an error when I tried to restore the original hosts file
back via spybot, so I had to do it manually.