I run Spysweeper from webroot and it works OK. It is a pay subsription but a free download. Make sure you run it right away because webroot will load the latest protections before the first scan. After that you must pay for the latest protections.
The second spyware tool is from Giant and it works really well but only for 14 days then you must pay for it. I like it better that spysweeper but it doesn’t run after 14 days.
Also, look into the yahoo toolbar. It is free and has pop up blocker and spyware dection. I do not use it but I have heard good things.