Program.cs

using Microsoft.Win32;
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Drawing;
using System.Runtime.InteropServices;

namespace SwitchExplorer
{
    internal class Program
    {
        static string myName = typeof(Program).Namespace;
        static string myExe = System.Reflection.Assembly.GetExecutingAssembly().Location;
        static float ScaleFactor = GetScale();
        static bool Dark = isDark();
        static bool Win10Explorer;
        static bool Win10ContextMenu;

        static string E10A = @"Software\Classes\CLSID\{2aa9162e-c906-4dd9-ad0b-3d24a8eef5a0}";
        static string E10B = @"Software\Classes\CLSID\{6480100b-5a83-4d1e-9f69-8ae5a88e9a33}";
        static string CCMA = @"Software\Classes\CLSID\{86CA1AA0-34AA-4E8B-A509-50C905BAE2A2}";
        static string CCMB = $@"{CCMA}\InprocServer32";
        static string ADVK = @"Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced";
        static string TBAR = @"Software\Microsoft\Internet Explorer\Toolbar";

        static string Option = "";

        static bool e10;
		static bool e11;
		static bool c10;
		static bool c11;
        static bool OK2Reload = true;
        static bool restart = false;

        static string myKey = @"HKEY_CURRENT_USER\Software\SwitchExplorer";

        // Import the necessary Windows API functions
        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll")]
        public static extern bool IsWindowVisible(IntPtr hWnd);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

        // Message constants
        const uint WM_CLOSE = 0x0010;

        [STAThread]
        static void Main(string[] args)
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            string NTkey = @"HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion";
            int buildNumber = int.Parse(Registry.GetValue(NTkey, "CurrentBuild", "").ToString());
            int UBR = int.Parse(Registry.GetValue(NTkey, "UBR", "").ToString());

            if (buildNumber < 21996)
            {
                MessageBox.Show("Windows 11 required", myName);
                return;
            }

            using (RegistryKey key = Registry.CurrentUser.OpenSubKey(E10A))
            {
                Win10Explorer = key != null;
            }

            using (RegistryKey key = Registry.CurrentUser.OpenSubKey(CCMB))
            {
                Win10ContextMenu = key != null;
            }

            if (args.Length == 0)
            {
                try { restart = (int)Registry.GetValue(myKey, "RestartExplorer", 0) == 1; } catch { }
                var optionsDialog = new OptionsDialog();
                optionsDialog.ShowDialog();
                return;
            }
			
			e10 = Win10Explorer;
			e11 = !Win10Explorer;
			c10 = Win10ContextMenu;
			c11 = !Win10ContextMenu;

            for (int i = 0; i < args.Length; i++)
            {
                Option = args[i].ToLower();
                if (Option == "/e10") { e10 = true; }
                if (Option == "/e11") { e11 = true; }
                if (Option == "/c10") { c10 = true; }
                if (Option == "/c11") { c11 = true; }
                if (Option == "/x") { OK2Reload = false; }
                if (Option == "/r") { restart = true; }
            }

            SaveSettings();
        }

        // Get current screen scaling factor
        static float GetScale()
        {
            using (Graphics graphics = Graphics.FromHwnd(IntPtr.Zero))
            {
                float dpiX = graphics.DpiX;
                return dpiX / 96;
            }
        }

        // Determine if dark colors (theme) are being used
        public static bool isDark()
        {
            const string keyPath = @"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize";
            const string valueName = "AppsUseLightTheme";

            using (RegistryKey key = Registry.CurrentUser.OpenSubKey(keyPath))
            {
                if (key != null)
                {
                    object value = key.GetValue(valueName);
                    if (value is int intValue)
                    {
                        return intValue == 0;
                    }
                }
            }
            return false; // Return false if the key or value is missing
        }

        // Make dialog title bar black
        public enum DWMWINDOWATTRIBUTE : uint
        {
            DWMWA_USE_IMMERSIVE_DARK_MODE = 20,
        }

        [DllImport("dwmapi.dll", CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void DwmSetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE attribute, ref int pvAttribute, uint cbAttribute);

        static void DarkTitleBar(IntPtr hWnd)
        {
            var preference = Convert.ToInt32(true);
            DwmSetWindowAttribute(hWnd, DWMWINDOWATTRIBUTE.DWMWA_USE_IMMERSIVE_DARK_MODE, ref preference, sizeof(uint));

        }
        static void SaveSettings()
        {
            string H = @"HKEY_CURRENT_USER\";

            if (c10 && !Win10ContextMenu)
            {
                try
                {
                    Registry.SetValue($@"{H}{CCMB}", "", "", RegistryValueKind.String);
                }
                catch
                {
                }
            }

            if (c11 && Win10ContextMenu)
            {
                try
                {
                    Registry.CurrentUser.DeleteSubKeyTree(CCMA, false);
                }
                catch
                {
                }
            }

            if (e10 && !Win10Explorer)
            {
                Registry.SetValue($@"{H}{E10A}\InProcServer32", "", "", RegistryValueKind.String);
                Registry.SetValue($@"{H}{E10B}\InProcServer32", "", "", RegistryValueKind.String);

                byte[] binaryData = { 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x10, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x07, 0x00, 0x00, 0x5e, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
                string SHBR = $@"{H}Software\Microsoft\Internet Explorer\Toolbar\ShellBrowser";
                Registry.SetValue(SHBR, "ITBar7Layout", binaryData, RegistryValueKind.Binary);
            }

            if (e11 && Win10Explorer)
            {
                try
                {
                    Registry.CurrentUser.DeleteSubKeyTree(E10A, false);
                    Registry.CurrentUser.DeleteSubKeyTree(E10B, false);
                }
                catch
                {
                }
            }

            Registry.SetValue($@"{H}{ADVK}", "AlwaysShowMenus", 0, RegistryValueKind.DWord);
            Registry.SetValue($@"{H}{TBAR}", "Locked", 1, RegistryValueKind.DWord);

            if (OK2Reload || restart)
            {
                CloseExplorerWindows();
                if (restart) RestartExplorer();
                Process.Start("explorer.exe", AppDomain.CurrentDomain.BaseDirectory);
            }
        }

        static void CloseExplorerWindows()
        {
            IntPtr hWnd = FindWindow("CabinetWClass", null);

            while (hWnd != IntPtr.Zero)
            {
                try
                {
                    if (IsWindowVisible(hWnd))
                    {
                        PostMessage(hWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
                    }
                    hWnd = FindWindowEx(IntPtr.Zero, hWnd, "CabinetWClass", null);
                }
                catch (Exception)
                {
                }
            }
        }

        static void RestartExplorer()
        {
            var processes = Process.GetProcessesByName("explorer");
            foreach (var process in processes)
            {
                try
                {
                    process.Kill();
                    process.WaitForExit();
                }
                catch { }
            }
        }

        // Dialog for selecting Options
        public class OptionsDialog : Form
        {
            private RadioButton Win10ExplorerRadioButton;
            private RadioButton Win11ExplorerRadioButton;
            private RadioButton Win10ContextRadioButton;
            private RadioButton Win11ContextRadioButton;
            private Button buttonOK;
            private CheckBox restartCheckBox;

            public OptionsDialog()
            {
                InitializeComponents();
                Win10ExplorerRadioButton.Checked = Win10Explorer;
                Win10ContextRadioButton.Checked = Win10ContextMenu;
                Win11ExplorerRadioButton.Checked = !Win10Explorer;
                Win11ContextRadioButton.Checked = !Win10ContextMenu;
                restartCheckBox.Checked = restart;
            }

            private void InitializeComponents()
            {
                Icon = Icon.ExtractAssociatedIcon(myExe);
                Text = myName;
                FormBorderStyle = FormBorderStyle.FixedDialog;
                MaximizeBox = false;
                MinimizeBox = false;
                StartPosition = FormStartPosition.Manual;
                Width = (int)(300 * ScaleFactor);
                Height = (int)(300 * ScaleFactor);
                Font = new Font("Segoe UI", 10);

                //Explorer Group

                var ExplorerGroupBox = new GroupBox
                {
                    Name = "ExplorerGroupBox",
                    Text = "Select Explorer Type",
                    Location = new Point((int)(10 * ScaleFactor), (int)(10 * ScaleFactor)),
                    Width = Width - (int)(40 * ScaleFactor),
                    Height = (int)(80 * ScaleFactor)
                };

                if (Dark) { ExplorerGroupBox.ForeColor = Color.White; }

                Win10ExplorerRadioButton = new RadioButton
                {
                    Text = "Windows 10",
                    Location = new Point((int)(10 * ScaleFactor), (int)(20 * ScaleFactor)),
                    AutoSize = true
                };

                Win11ExplorerRadioButton = new RadioButton
                {
                    Text = "Windows 11",
                    Location = new Point((int)(10 * ScaleFactor), (int)(40 * ScaleFactor)),
                    AutoSize = true
                };

                ExplorerGroupBox.Controls.Add(Win10ExplorerRadioButton);
                ExplorerGroupBox.Controls.Add(Win11ExplorerRadioButton);

                //Context Group

                var contextMenuGroupBox = new GroupBox
                {
                    Name = "contextMenuGroupBox",
                    Text = "Select Context Menu Type",
                    Left = (int)(10 * ScaleFactor),
                    Top = (int)(100 * ScaleFactor),
                    Width = Width - (int)(40 * ScaleFactor),
                    Height = (int)(80 * ScaleFactor)
                };

                if (Dark) { contextMenuGroupBox.ForeColor = Color.White; }

                Win10ContextRadioButton = new RadioButton
                {
                    Text = "Windows 10",
                    Left = (int)(10 * ScaleFactor),
                    Top = (int)(20 * ScaleFactor),
                    AutoSize = true
                };

                Win11ContextRadioButton = new RadioButton
                {
                    Text = "Windows 11",
                    Left = (int)(10 * ScaleFactor),
                    Top = (int)(40 * ScaleFactor),
                    AutoSize = true
                };

                contextMenuGroupBox.Controls.Add(Win10ContextRadioButton);
                contextMenuGroupBox.Controls.Add(Win11ContextRadioButton);

                // Restart Explorer checkbox

                restartCheckBox = new CheckBox
                {
                    Text = "Restart Explorer",
                    Left = (int)(10 * ScaleFactor),
                    Top = (int)(190 * ScaleFactor),
					AutoSize = true
                };
                if (Dark) restartCheckBox.ForeColor = Color.White;
                Controls.Add(restartCheckBox);

                if (Dark)
                {
                    DarkTitleBar(Handle);
                    BackColor = Color.FromArgb(32, 32, 32);
                    ForeColor = Color.White;
                }

                Controls.Add(ExplorerGroupBox);
                Controls.Add(contextMenuGroupBox);

                buttonOK = new Button();
                buttonOK.Text = "OK";
                buttonOK.Left = (Width - (int)(80 * ScaleFactor)) / 2;
                buttonOK.Top = Height - (int)(74 * ScaleFactor);
                buttonOK.Width = (int)(75 * ScaleFactor);
                buttonOK.Height = (int)(26 * ScaleFactor);
                buttonOK.Click += new EventHandler(buttonOK_Click);
                buttonOK.Font = new Font("Segoe UI", 9);
                if (Dark)
                {
                    buttonOK.FlatStyle = FlatStyle.Flat;
                    buttonOK.FlatAppearance.BorderColor = SystemColors.Highlight;
                    buttonOK.FlatAppearance.BorderSize = 1;
                    buttonOK.BackColor = Color.FromArgb(60, 60, 60);
                    buttonOK.FlatAppearance.MouseOverBackColor = Color.Black;
                }
                Controls.Add(buttonOK);

                Point cursorPosition = Cursor.Position;
                int dialogX = Cursor.Position.X - Width / 2;
                int dialogY = Cursor.Position.Y - Height / 2;
                Screen screen = Screen.FromPoint(cursorPosition);
                int screenWidth = screen.WorkingArea.Width;
                int screenHeight = screen.WorkingArea.Height;
                int baseX = screen.Bounds.X;
                int baseY = screen.Bounds.Y;
                dialogX = Math.Max(baseX, Math.Min(baseX + screenWidth - Width, dialogX));
                dialogY = Math.Max(baseY, Math.Min(baseY + screenHeight - Height, dialogY));
                Location = new Point(dialogX, dialogY);
            }

            private void buttonOK_Click(object sender, EventArgs e)
            {
				e10 = Win10ExplorerRadioButton.Checked;
				e11 = Win11ExplorerRadioButton.Checked;
				c10 = Win10ContextRadioButton.Checked;
				c11 = Win11ContextRadioButton.Checked;
                restart = restartCheckBox.Checked;

                Registry.SetValue(myKey, "RestartExplorer", restart, RegistryValueKind.DWord);
                SaveSettings();
                Close();
            }
        }
    }
}