Change screen Orientation with powershell - Where are the registry values stored?

Hej from Sweden,

I am trying out the code from the reference post: Powershell script to change screen Orientation

The script works. The goal is to make sure that the rotation is either landscape - default or portrait 90 degrees clockwise.

I need to either change the current code to just allow 2 values or make sure that the script only runs once.

Either way, I need to know where the registry keys are stored for the CDS_UPDATEREGISTRY. Although I cannot figure out where in the registry the value change for each rotation are stored in the registry?

Does anyone by any chance know where the values are stores?

Code:

Function Set-ScreenResolutionAndOrientation { 

<# 
    .Synopsis 
        Sets the Screen Resolution of the primary monitor 
    .Description 
        Uses Pinvoke and ChangeDisplaySettings Win32API to make the change 
    .Example 
        Set-ScreenResolutionAndOrientation         
#>

$pinvokeCode = @" 

using System; 
using System.Runtime.InteropServices; 

namespace Resolution 
{ 

    [StructLayout(LayoutKind.Sequential)] 
    public struct DEVMODE 
    { 
       [MarshalAs(UnmanagedType.ByValTStr,SizeConst=32)]
       public string dmDeviceName;

       public short  dmSpecVersion;
       public short  dmDriverVersion;
       public short  dmSize;
       public short  dmDriverExtra;
       public int    dmFields;
       public int    dmPositionX;
       public int    dmPositionY;
       public int    dmDisplayOrientation;
       public int    dmDisplayFixedOutput;
       public short  dmColor;
       public short  dmDuplex;
       public short  dmYResolution;
       public short  dmTTOption;
       public short  dmCollate;

       [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
       public string dmFormName;

       public short  dmLogPixels;
       public short  dmBitsPerPel;
       public int    dmPelsWidth;
       public int    dmPelsHeight;
       public int    dmDisplayFlags;
       public int    dmDisplayFrequency;
       public int    dmICMMethod;
       public int    dmICMIntent;
       public int    dmMediaType;
       public int    dmDitherType;
       public int    dmReserved1;
       public int    dmReserved2;
       public int    dmPanningWidth;
       public int    dmPanningHeight;
    }; 

    class NativeMethods 
    { 
        [DllImport("user32.dll")] 
        public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE devMode); 
        [DllImport("user32.dll")] 
        public static extern int ChangeDisplaySettings(ref DEVMODE devMode, int flags); 

        public const int ENUM_CURRENT_SETTINGS = -1; 
        public const int CDS_UPDATEREGISTRY = 0x01; 
        public const int CDS_TEST = 0x02; 
        public const int DISP_CHANGE_SUCCESSFUL = 0; 
        public const int DISP_CHANGE_RESTART = 1; 
        public const int DISP_CHANGE_FAILED = -1;
        public const int DMDO_DEFAULT = 0;
        public const int DMDO_90 = 1;
        public const int DMDO_180 = 2;
        public const int DMDO_270 = 3;
    } 



    public class PrmaryScreenResolution 
    { 
        static public string ChangeResolution() 
        { 

            DEVMODE dm = GetDevMode(); 

            if (0 != NativeMethods.EnumDisplaySettings(null, NativeMethods.ENUM_CURRENT_SETTINGS, ref dm)) 
            {

                // swap width and height
                int temp = dm.dmPelsHeight;
                dm.dmPelsHeight = dm.dmPelsWidth;
                dm.dmPelsWidth = temp;

                // determine new orientation based on the current orientation
                switch(dm.dmDisplayOrientation)
                {
                    case NativeMethods.DMDO_DEFAULT:
                        dm.dmDisplayOrientation = NativeMethods.DMDO_270;
                        break;
                    case NativeMethods.DMDO_270:
                        dm.dmDisplayOrientation = NativeMethods.DMDO_180;
                        break;
                    case NativeMethods.DMDO_180:
                        dm.dmDisplayOrientation = NativeMethods.DMDO_90;
                        break;
                    case NativeMethods.DMDO_90:
                        dm.dmDisplayOrientation = NativeMethods.DMDO_DEFAULT;
                        break;
                    default:
                        // unknown orientation value
                        // add exception handling here
                        break;
                }


                int iRet = NativeMethods.ChangeDisplaySettings(ref dm, NativeMethods.CDS_TEST); 

                if (iRet == NativeMethods.DISP_CHANGE_FAILED) 
                { 
                    return "Unable To Process Your Request. Sorry For This Inconvenience."; 
                } 
                else 
                { 
                    iRet = NativeMethods.ChangeDisplaySettings(ref dm, NativeMethods.CDS_UPDATEREGISTRY); 
                    switch (iRet) 
                    { 
                        case NativeMethods.DISP_CHANGE_SUCCESSFUL: 
                            { 
                                return "Success"; 
                            } 
                        case NativeMethods.DISP_CHANGE_RESTART: 
                            { 
                                return "You Need To Reboot For The Change To Happen.\n If You Feel Any Problem After Rebooting Your Machine\nThen Try To Change Resolution In Safe Mode."; 
                            } 
                        default: 
                            { 
                                return "Failed To Change The Resolution"; 
                            } 
                    } 

                } 


            } 
            else 
            { 
                return "Failed To Change The Resolution."; 
            } 
        } 

        private static DEVMODE GetDevMode() 
        { 
            DEVMODE dm = new DEVMODE(); 
            dm.dmDeviceName = new String(new char[32]); 
            dm.dmFormName = new String(new char[32]); 
            dm.dmSize = (short)Marshal.SizeOf(dm); 
            return dm; 
        } 
    } 
} 

"@ 

Add-Type $pinvokeCode -ErrorAction SilentlyContinue 
[Resolution.PrmaryScreenResolution]::ChangeResolution() 
}

Set-ScreenResolutionAndOrientation

<#
   0 = Default
   1 = 90°Left (Counter-Clockwise)
   2 = 180°
   3 = 270° (90°Right Clockwise)
#> 

By adding the values 0, 1, 2, 3 as a parameter in ChangeResolution(0) the function will enable the script to define the portrait or landscape orientation.