First thing I would recommend is removing all things Norton from your system. Seriously.
In addition to adaware, spybot and some other good programs mentioned above the very best thing for your system is to hawkeye
everything that passes your screen. You don't have to click Yes to download lyrics. Click the X a couple of times and the nag goes away. Don't click No or Cancel on these boxes, those can be set to whatever value the page author wants.
If you regularly update your system at Windows Update and your online enhancements like java, shockwave, etc. you should rarely encounter a site that says something on your system needs to be "updated".
Yes there
are some scumware out there that can install without user intervention, but most spyware on people's systems that I've cleaned don't fall into this category
