Today, I saw an ad promoting Spyblocs (web address as a free way to eliminate spyware from your system. I started the download process, but when I got to the point where I had to register, I found out it wasn't free after all and so I cancelled. However, some part of it must still be on my system despite my having uninstalled it, because now, I can't stay on the Yahoo! home page for more than three seconds without my screen switching over to the About.blank search engine page, and my system giving me umpty-hundred pop-ups advertising the Spyblocs system. Can someone tell me how to get rid of this nonsense and get my computer back to normal?