This reader question is a good jumping-off point to talk about an important point for new Windows 10 users: “How do I stop advertisements from coming up in Yahoo mail. I did not have this in Windows 7 before upgradeing to 10. It is very annoying.”
Windows 10 doesn’t change anything about your Yahoo Mail, Gmail, Outlook.com mail or any other email that you access via a browser interface. If something is different, I suspect that you may have switched browsers without meaning to. The browser you were using before you upgraded may have had an ad-blocking extension in place.
If you’re accessing your mail using the Edge browser, this extension is not installed, so the pop-ups aren’t being blocked. Here’s what the icon to open Edge looks like.
Try opening up the browser you were using before you upgraded to Windows 10. If you were using Internet Explorer, Chrome, or Firefox, they are all still there on your PC. Just type the name of the browser in the search box and click on the result.