Post a screenshot of C9, MSN, and Desktop side-by-side.
As for IE setting, you have TWO places to set.
- Font size.
As for system wide font size, including Desktop, Visual Studios, and Windows Explore, change DPI in control panel. I used to set 125% on my 24in 1080p monitor. Once I get to 27in 1080p, I get my DPI down to 110%.
And if you are using MetroIE in CP build, MetroIE is not as smart, it doesn't default your zoom to match your DPI. You need to zoom manually.