More usefully....
I have got firefox but there's still the same problem using it. MS word also looks a bit odd.
....this is very useful information, if the problem persists with more than one application/program then it suggests its not a problem with that program (i.e its NOT the "internet" that is broken).
From the screenshot it may suggest that you've screwed up the display drivers or changed some rendition settings. Without knowing
exactly what you've done its hard to diagnose (especially so for me as I don't use M$-Windoze). I'd suggest some heavily googling and/or M$-support site itself. It may be completely unrelated to the windows narrator.
Check to see what updates have been installed between now and when the problem didn't exist. Try rolling back to an auto-backup before the problem started occurring.