Here's the scenario: one of my students showed me that every time she opened Chrome browser, a bunch of pop-up ads cluttered up her screen. There were ads on both the left and right sides, and one at the bottom. There's nothing that irritates me in quite the same way as intrusive unwarranted pop-ups that are difficult to remove. There's just something about it that gets under my skin.
So I started investigating. If you right-click on anything in Chrome browser, you can choose to "inspect element." What that will do is show you some of the actual code that's going into what you're seeing. This turned out to be useful (and it wasn't the first thing I tried; it was the first thing that worked), since it showed me the source of the ads: something called Superfish. Apparently it can get worse that what my student was facing (I'll be sure to let her know just how lucky she was).
|This fish is really not that super.|
This is apparently something that gets piggybacked in on other Chrome extensions and themes. I had checked all of the student's enabled extensions and themes, and tried to remove all of them. Unfortunately, the theme causing the problems ended up being very persistent; it didn't want to be disabled, deleted, or tinkered with in any way.
I tried signing out. I tried deleting the Chrome preferences file (an old OS X trick that sometimes works). The problem is that Chrome associates your preferences with your profile, not with your computer. Okay, that's not really a problem - it's actually one of the things I love about Chrome. It just means that treating this the same way I'd try to treat a computer virus wouldn't work.
What ended up doing the trick was opening up the Chrome settings. At the bottom of the page, there's a link to show more advanced settings. Clicking on that reveals more options, and scrolling down to the bottom of that window reveals the magic button: "Reset browser settings." This warned me that I'd lose all my bookmarks and extensions (but that was kind of the point, so I didn't mind). I did it, then had my student sign back into Chrome once more.
But, lo and behold, it didn't lose all her bookmarks. It did disable all the extensions, but by this point I had gotten rid of everything, so that wasn't an issue. But it solved the problem! Hooray!
I hope if you face a similar situation, this bit of insight might help.