Attached Link: http://kb.mozillazine.org/Setting_Your_Default_Browser

Let's not jump to conclusions. I believe there's also been a Flash update recently which may be to blame - and anyone who was fed IE11 would have got the latest Flash along with it.

I don't think it's possible to fully uninstall IE, but there are articles around the web telling you how to disable it, at least. However if you use a recent version of Poser that doesn't sound like a good idea.

There are ways to tell Windows which is going to be your default browser - the link has some information on that.