I've used spybot. I use AVG virus software which I think does a decent job of noticing things, but who knows. Yes, anyone who isn't familiar with the immunize function of those programs learn them soon. Another thing I've used with IE(version 6 only) is gogodata adbuster. It's a popup blocker that works really well. It also has an online spyware searcher as well as an immunize function. There are a few things out there that are just too stubborn for any free programs. At least once infected. You might already know this, but if you know what the files are you can usually manually remove them from the registry by booting to safe mode. My mom's pc
had something called tvmedia or somrething that I could not close, shutdown, or even block from starting up. Try to delete it from the registry, it just pops back up. But in safe mode you click delete it's gone... Good luck with it. I've also heard great things about spysweeper.