So the attempts to get you to download system defender is site specific....
If you are using Firefox you should try NoScript add-on and Adblock Plus Add-on. Especially NoScript. It blocks
all scripting from running except the scripts you specifically allow. Frankly, if I used Windows and had to choose
only one security program....it would be NoScript. There is a small learning curve...but it is worth it.
If you use Google Chrome, there are two script blockers and Adblock Plus - Chrome offered as Add-Ons.
I don't use Chrome so I won't suggest which script blocker to use in Chrome. Just be sure to get the extensions from
the Google site. Here's one...NotScripts - Chrome
Blocking Third Party/ ad/ tracking cookies may help, too. Disable third-party cookies in IE, Firefox, and Google Chrome | How To - CNET
“Every atom in your body came from a star that exploded and the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics...you are all stardust.”― Lawrence M. Krauss
A 1792 U.S. penny, designed in part by Thomas Jefferson and George Washington, reads “Liberty Parent of Science & Industry.”