You should use Ad-Aware (download site) to get rid of spyware running in the background. You might also want to keep the reference file up to date using Ref-Update.

If you feel pop-up ads are a nuisance, you can also download Proxomitron, which essentially uses proxy settings in your browser to filter out advertisements of all kinds, without having to completely disable javascript (which sadly, many pop-up tools do, and they advertise that they are doing much more). There may be some other tools out there as well, but this is one that I think you may like.