diff --git a/Setup/Runtime.cs b/Setup/Runtime.cs
deleted file mode 100644
index ed332a6..0000000
--- a/Setup/Runtime.cs
+++ /dev/null
@@ -1,169 +0,0 @@
-using System.ComponentModel;
-using System.Diagnostics;
-using System.IO;
-using System.Net;
-using System.Net.Http;
-using System.Runtime.InteropServices;
-using System.Security.Cryptography.X509Certificates;
-using Microsoft.Win32;
-
-namespace DeskCoreSetup;
-
-/// <summary>Prüft und installiert die von DeskCore benötigte "Microsoft .NET 9 Desktop Runtime".</summary>
-public static class Runtime
-{
-    public const string DisplayName = "Microsoft .NET 9 Desktop Runtime";
-    public const int Major = 9;
-    public const string DownloadPage = "https://dotnet.microsoft.com/de-de/download/dotnet/9.0";
-    // offizieller Microsoft-Kurzlink auf die jeweils aktuelle 9.0-Version
-    private const string InstallerUrl = "https://aka.ms/dotnet/9.0/windowsdesktop-runtime-win-x64.exe";
-
-    public static bool Is64BitWindows => Environment.Is64BitOperatingSystem;
-
-    public static bool IsInstalled
-    {
-        get
-        {
-            try
-            {
-                var dir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles),
-                    "dotnet", "shared", "Microsoft.WindowsDesktop.App");
-                if (Directory.Exists(dir) && Directory.GetDirectories(dir).Any(d => Path.GetFileName(d).StartsWith($"{Major}.")))
-                    return true;
-            }
-            catch { }
-            try
-            {
-                using var hklm = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32);
-                using var k = hklm.OpenSubKey(@"SOFTWARE\dotnet\Setup\InstalledVersions\x64\sharedfx\Microsoft.WindowsDesktop.App");
-                if (k?.GetValueNames().Any(n => n.StartsWith($"{Major}.")) == true) return true;
-            }
-            catch { }
-            return false;
-        }
-    }
-
-    /// <summary>Lädt die Laufzeit von Microsoft und installiert sie (Windows fragt einmal nach Administratorrechten).</summary>
-    public static void Install(Action<double, string> progress)
-    {
-        ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12;
-        var file = Path.Combine(Path.GetTempPath(), $"windowsdesktop-runtime-{Major}-win-x64.exe");
-
-        using (var http = new HttpClient { Timeout = TimeSpan.FromMinutes(20) })
-        {
-            http.DefaultRequestHeaders.UserAgent.ParseAdd("DeskCore-Setup");
-            using var resp = http.GetAsync(InstallerUrl, HttpCompletionOption.ResponseHeadersRead).GetAwaiter().GetResult();
-            resp.EnsureSuccessStatusCode();
-            long total = resp.Content.Headers.ContentLength ?? 0;
-            using var input = resp.Content.ReadAsStreamAsync().GetAwaiter().GetResult();
-            using var output = File.Create(file);
-            var buffer = new byte[81920];
-            long done = 0;
-            int read;
-            while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
-            {
-                output.Write(buffer, 0, read);
-                done += read;
-                progress(total > 0 ? (double)done / total : 0,
-                    total > 0 ? $"{DisplayName} wird heruntergeladen … {done / 1048576} von {total / 1048576} MB"
-                              : $"{DisplayName} wird heruntergeladen … {done / 1048576} MB");
-            }
-        }
-
-        // Sicherheit: nur ausführen, wenn die Datei gültig von Microsoft signiert ist
-        if (!IsSignedByMicrosoft(file))
-        {
-            try { File.Delete(file); } catch { }
-            throw new InvalidOperationException("Die heruntergeladene Datei ist nicht gültig von Microsoft signiert und wurde nicht ausgeführt.");
-        }
-
-        progress(1, $"{DisplayName} wird installiert – bitte die Windows-Abfrage bestätigen …");
-        Process p;
-        try
-        {
-            p = Process.Start(new ProcessStartInfo(file, "/install /quiet /norestart") { UseShellExecute = true, Verb = "runas" })!;
-        }
-        catch (Win32Exception ex) when (ex.NativeErrorCode == 1223)
-        {
-            throw new InvalidOperationException($"Die Installation von {DisplayName} wurde abgebrochen.");
-        }
-        p.WaitForExit();
-        try { File.Delete(file); } catch { }
-        // 0 = ok, 3010/1641 = ok, Neustart empfohlen
-        if (p.ExitCode is not (0 or 3010 or 1641) || !IsInstalled)
-            throw new InvalidOperationException($"{DisplayName} konnte nicht installiert werden (Code {p.ExitCode}).");
-    }
-
-    // ---------- Signaturprüfung (WinVerifyTrust) ----------
-
-    private static bool IsSignedByMicrosoft(string file)
-    {
-        try
-        {
-            var subject = X509Certificate.CreateFromSignedFile(file).Subject;
-            if (subject.IndexOf("O=Microsoft Corporation", StringComparison.OrdinalIgnoreCase) < 0) return false;
-        }
-        catch { return false; }
-        return VerifyTrust(file);
-    }
-
-    private static bool VerifyTrust(string file)
-    {
-        var fileInfo = new WINTRUST_FILE_INFO
-        {
-            cbStruct = (uint)Marshal.SizeOf<WINTRUST_FILE_INFO>(),
-            pcwszFilePath = file,
-        };
-        var pFile = Marshal.AllocHGlobal(Marshal.SizeOf<WINTRUST_FILE_INFO>());
-        try
-        {
-            Marshal.StructureToPtr(fileInfo, pFile, false);
-            var data = new WINTRUST_DATA
-            {
-                cbStruct = (uint)Marshal.SizeOf<WINTRUST_DATA>(),
-                dwUIChoice = 2,            // WTD_UI_NONE
-                fdwRevocationChecks = 0,   // WTD_REVOKE_NONE
-                dwUnionChoice = 1,         // WTD_CHOICE_FILE
-                pFile = pFile,
-                dwStateAction = 0,
-                dwProvFlags = 0x40,        // WTD_SAFER_FLAG
-            };
-            var action = new Guid("00AAC56B-CD44-11d0-8CC2-00C04FC295EE"); // WINTRUST_ACTION_GENERIC_VERIFY_V2
-            return WinVerifyTrust(IntPtr.Zero, ref action, ref data) == 0;
-        }
-        finally
-        {
-            Marshal.FreeHGlobal(pFile);
-        }
-    }
-
-    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
-    private struct WINTRUST_FILE_INFO
-    {
-        public uint cbStruct;
-        public string pcwszFilePath;
-        public IntPtr hFile;
-        public IntPtr pgKnownSubject;
-    }
-
-    [StructLayout(LayoutKind.Sequential)]
-    private struct WINTRUST_DATA
-    {
-        public uint cbStruct;
-        public IntPtr pPolicyCallbackData;
-        public IntPtr pSIPClientData;
-        public uint dwUIChoice;
-        public uint fdwRevocationChecks;
-        public uint dwUnionChoice;
-        public IntPtr pFile;
-        public uint dwStateAction;
-        public IntPtr hWVTStateData;
-        public IntPtr pwszURLReference;
-        public uint dwProvFlags;
-        public uint dwUIContext;
-        public IntPtr pSignatureSettings;
-    }
-
-    [DllImport("wintrust.dll", ExactSpelling = true, SetLastError = false, CharSet = CharSet.Unicode)]
-    private static extern int WinVerifyTrust(IntPtr hwnd, ref Guid pgActionID, ref WINTRUST_DATA pWVTData);
-}