Sample AHK script to change windows display scaling using https://github.com/imniko/SetDPI , compatible with AHK version 1.x

change-dpi-scale.ahk

#persistent

current_scale := 100 ; scale value you are currently in
next_scale := 125 ; scale value you want to switch to next
is_scaled := 0

return

; Ctrl + Win + F1 toggles main monitor between 2 scale values
^#F1::
    if(is_scaled == 0)
        Run SetDpi.exe %next_scale%
    else
        Run SetDpi.exe %current_scale%
    is_scaled := !is_scaled
return

; Ctrl + Win + F2 sets 2nd monitor to a scale of 150
^#F2::
    Run SetDpi.exe 150 2
return