Hi, as you observe, the default font zoom is set at 120% but this may be too high for the combination of your native screen resolution and the Windows Magnification setting (e.g. 125% or 150%, set in the Windows Control Panel, Screen Resolution tool). Windows own screen magnification settings above 100% (i.e. separate from RDSS' magnification) may cause an otherwise HD quality screen (e.g. 1920 x 1080 resolution) to actually be less than that (e.g. 1080 vertical divided by 150% or 1.5 = effectively 720 vertical). And this would be less than required for 3 panels - unless you try to reduce the RDSS font magnification.
Long way of saying - do try to tinker with the combination of Windows font magnification and RDSS' font magnification to get screen display sizes such that you can use the 3 panel layout. (Also consider a special glasses prescription, depending on age ...
)
cheers,
Ted