If you are currently using Microsoft's Internet Explorer as your browser I recommend that you try a different web browser....
Mozilla Firefox
It's pretty much agreed among most computer experts that the Firefox browser has fewer security holes than IE, as well as blocking pop up ads and other neat special features that you'll like...and it's FREE.
For more information, click here
IMPORTANT: Keep IE in your computer, you'll need it to up-date windows, but I suggest using the Firefox browser for most of your internet surfing.