Hi,
It's question beyond support but ...
Option #1:
Using IE CSS hacks you can create a short message inside custom module that would be displayed only for IE10 and IE11 users - add class name to that module. If you know CSS - handle & customize this:
.iebrowser { display:none; }
@media screen and (-ms-high-contrast: active), (-ms-high-contrast: none) {
.iebrowser { display:block !important; }
}
Option #2: You need popup module (for example PopUp Aholic module) and installed Advanced Module Manager (RegularLabs.com) - it allows you to set where the modules should be displayed, also by browser.