You can avoid seeing those popup ads and other ads. Simply install an ad blocker. Your router could be the problem. If the solutions below
don't block the ads then you should reset and resecure the router.
You can block third party cookies from installing. Those are the ad/ tracking cookies. Once you have blocked them from
installing, use CCleaner to remove the existing ones.
How to disable third-party cookies in all major web browsers
Use CCleaner to remove Temporary files, program caches, cookies, logs, etc. Use the Default settings. No need to use the
Registry Cleaning Tool...risky. Pay close attention while installing and UNcheck offers of toolbars....especially Google.
After install, open CCleaner and run by clicking on the Run Cleaner button in the bottom right corner.
CCleaner - PC Optimization and Cleaning - Free Download
If you don't have an ad blocker installed I suggest using Adblock Plus. Once installed click on the ABP icon at the top of your
browsers and choose Filter Preferences. Then UNcheck the box next to Allow some non-intrusive advertisements.
Adblock Plus - Chrome Web Store Adblock Plus :: Add-ons for Firefox Adblock Plus for Edge browser Adblock Plus for IE
For Firefox users I also recommend learning to use NoScript which is an excellent ad blocker and excellent security.
It will block web beacons and all of those malware scripts that attempt to install adware and malware on your computer by just visiting a compromised or
a criminal's website. NoScript Security Suite :: Add-ons for Firefox
From the Web:
A Web beacon is an often-transparent graphic image, usually no larger than 1 pixel x 1 pixel, that is placed on a Web site or in an email that is used to monitor the behavior of the user visiting the Web site or sending the email. It is often used in combination with cookies.
Scan for adware and malware using these programs:
Malwarebytes AdwCleaner Junkware Removal Tool