Hi Ruko,
Welcome to the Forum.
From your description it sounds to me like what you are seeing is
in-text advertising. Quite a few websites now use JavaScripts to dynamically locate key words in an article you are reading, which then
double-underscores these key words to allow for a pop-up informational link. Generally, these pop ups will take you to more information on the topic you are exploring, but can also include ads as you have described.
Most of these types of sites will have a
Terms of Service (TOS) agreement, or a
Privacy Statement or a link to
learn more, each of which will offer an
opt out option, which is designed to turn this feature off.
Some third party app downloads, and some less well-behaved websites will force a install of a third party app that will generate these double underscored keywords too. An example of such an app is
Text-Enhance so you could
right-click on
Start > select
Settings > select
Apps and review what apps are installed on your System, as it could be a simple case of uninstalling such an app if its sneaked onto your computer.
Alternatively, using apps like Ad-Aware, CCleaner can detect these apps and offer to remove them for you.
Note: Text-Enhance can also be installed as a
Browser Helper Object as opposed to an app. Here are two links to articles on how to remove Text-Enhance should it have snuck onto your computer or embedded itself into your web browser.
Regards,
Regedit32