Well indeed you can.
You can configure your TCP/IP settings with the DOS command "ipconfig".
Then you can fire up DOS "ftp" and download Firefox from the Mozilla ftp server:
Index of ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/
Once downloaded via DOS ftp, you install Firefox.
So unless the EU considers MS-DOS under Windows to be "anticompetetive" - or maybe that Windows itself is "a monopoly" - you can indeed make use of many browsers without resorting to IE in any way shape or form, ever.
You can also delete the IE icons from you Windows Deskstop and Start Menu (as I did long ago) and be done with it almost forever.
The EU is fighting an amazingly stupid battle that was decided by the American computer user (aka "the American computer buyer") more than a decade ago, back in the days when there were first several GUIs (VisiOn, etc) and later many browsers (Netscape, Mosaic, etc).