AHK - Change Monitor Refreshrate

VK91::SetRefreshrateMainMonitor(120) ; SL
+VK91::SetRefreshrateMainMonitor(165) ; shift+SL
#VK91::CheckMonitors() ; win+SL


SetRefreshrateMainMonitor(Refreshrate) {
    SysGet, Monitor, MonitorPrimary
    ; Monitor := 2
    Refreshrate := Refreshrate

    SysGet, MonitorCount, MonitorCount
    If (Monitor > MonitorCount OR Monitor == 0 OR Monitor < -1) {
        TrayTip, AHK Monitor Change, Failed: Monitor Count incorrect, 5
    }
    EnumDisplayDevices(Monitor, DeviceName, StateFlags)
    ChangeRefreshrate(DeviceName, Refreshrate)
    return
}

CheckMonitors() {
    text := ""
    TotalPixels := ""
    PixelsPerSecond := ""
    Loop {
        if ! EnumDisplayDevices(A_Index, DeviceName, StateFlags)
            break
        if (StateFlags & 4) { ; text .= "Primary display device is " DeviceName "`n"
            ReadMonitor(DeviceName, Msg, Pixels, Pps)
            TotalPixels += Pixels
            PixelsPerSecond += Pps
            text .= "Monitor " A_Index " " Msg "`n"
        }
        else if (StateFlags & 1){ ; text .= "The desktop extends onto " DeviceName "`n"
            ReadMonitor(DeviceName, Msg, Pixels, Pps)
            TotalPixels += Pixels
            PixelsPerSecond += Pps
            text .= "Monitor " A_Index " " Msg "`n"
        }
        else if (StateFlags & 8){ ; text .= DeviceName " is a pseudo-device`n"
        }
        else{ ; text .= DeviceName " is disabled`n"
        }
    }
    TotalPixels := ThousandsSep(TotalPixels)
    PixelsPerSecond := ThousandsSep(PixelsPerSecond)
    MsgBox, 0, AHK Read Monitor Settings, %text% `n`n Total Pixels %TotalPixels% `n Pixels per Second %PixelsPerSecond%
    return
}

ThousandsSep(x, s=".") {
    return RegExReplace(x, "\G\d+?(?=(\d{3})+(?:\D|$))", "$0" s)
}

ChangeRefreshrate(MonitorName, refreshRate) {
    VarSetCapacity(dM,156,0),
    NumPut(156,2,&dM,36)
    DllCall( "EnumDisplaySettingsA", Str, MonitorName, UInt, -1, UInt, &dM),
    NumPut(0x5c0000,dM,40)
    NumPut(refreshRate,dM,120)
    ; Return DllCall( "ChangeDisplaySettingsA", UInt,&dM, UInt,0 )
    Return DllCall( "ChangeDisplaySettingsExA", Str, MonitorName, UInt,&dM, UInt,0, UInt,0 )
}

ReadMonitor(MonitorName, ByRef Msg, ByRef Pixels, ByRef Pps) {
    Msg := ""
    Pixels := 0
    Pps := 0
    VarSetCapacity(dM,156,0),
    NumPut(156,2,&dM,36)
    DllCall( "EnumDisplaySettingsA", Str, MonitorName, UInt, -1, UInt, &dM),
    Out_1:=NumGet(&dM,108,"uint4")  ; ScreeWidth
    Out_2:=NumGet(&dM,112,"uint4")  ; ScreenHeight
    ; Out_3:=NumGet(&dM,104,"uint4")    ; ColorDepth
    Out_4:=NumGet(&dM,120,"uint4")  ; Frequency
    ; TrayTip, AHK Read Monitor Settings, %Out_1%x%Out_2% @ %Out_3%bit %Out_4%Hz, 5
    ; Msg := Out_1 "x" Out_2 " @ " Out_3 "bit " Out_4 "Hz"
    Msg := Out_1 "x" Out_2 " @ " Out_4 " Hz"
    Pixels := Out_1 * Out_2
    Pps := Pixels * Out_4
    Return
}

EnumDisplayDevices(Index, ByRef DeviceName, ByRef StateFlags:="", ByRef DeviceKey:="") {
    VarSetCapacity(DisplayDevice, 424)
    NumPut(424, DisplayDevice, 0)
    StateFlags := 0     ; For consistency, clear StateFlags in case of failure.
    DeviceName := ""
    DeviceKey := ""

    if ! DllCall("EnumDisplayDevicesA"
        , "ptr", 0
        , "uint", Index-1
        , "ptr", &DisplayDevice
        , "uint", 0)
        return false

    StateFlags := NumGet(DisplayDevice, 164)
    ; DeviceName := StrGet(&DisplayDevice+4, 32, "cp0")
    DeviceName := StrGet(&DisplayDevice+4, 32)
    DeviceKey := StrGet(&DisplayDevice+296, 128, "cp0")
    if (SubStr(DeviceKey,1,18)="\Registry\Machine\")
        DeviceKey := SubStr(DeviceKey,19)
    return true
}