Hi, how do I stop the following popup in Edge.
This is an ATTACK - they are trying to trick you into installing malware. Do not click on the link, and do not visit the site again. (Microsoft now do updates to Flash for Edge if needed, you cannot download them).
By not going to the site. The message is not true, and not based on checking: it's an attack that will keep coming. Just don't go there. Be alert for attacks like this, millions of sites are infected.
Sadly, it happens from time to time - often due to sketchy ads - and there's not much that you can do (other than clicking the X next to the tab to close said tab). Never click Update or any of the other buttons - they all do the same.
If the URL doesn't feel right, leave the site.