If you have pop ups, you're more than likely infected with Malware. Every modern browser has a popup blocker AND is enabled by default.
Grab a free copy of malwarebytes at http://www.malwarebytes.org. Install and run the scan. Clean off anything it finds.
If you still can't get it, I recommend using a service to clean your PC, like http://www.cleanourcomputer.com they will clean up anything they find and they guarantee their work!
Adblock plus stops popups. For Firefox it is free, so i assume it is also for the other browsers. I also use Ghostery (freeware) that specifically blocks 'trackers", which sites like to attach. (it also lets you see a list of them as they are blocked) Right now I am blocking 3 from Yahoo Answers!
The major web browsers (Chrome, Firefox, IE, Safari) all have built-in popup blockers. Depending on which one you are using, google how to make sure it's enabled.
Try using an Ad Blocker.
Many are triggered by cookies buried in your HDD, so give it a good cleaning and see if that helps. I clean mine every couple of days.
ADblock plus (ABP) for Google CHROME —–
—– blocks all annoying ads, malware and tracking. Ad companies track your every move.