diff --git a/Ui/ShellUiHost.cs b/Ui/ShellUiHost.cs
index eae185d..cc888b1 100644
--- a/Ui/ShellUiHost.cs
+++ b/Ui/ShellUiHost.cs
@@ -28,6 +28,20 @@ namespace PolyTraderSharp.Ui
         /// <summary>Setzt das Hauptfenster (Launcher) – Ziel für <see cref="ActivateMain"/>.</summary>
         public void SetMainWindow(Form main) => _mainWindow = main;
 
+        /// <summary>
+        /// Fügt einem Fenster das gemeinsame „Fenster"-Menü hinzu (oberste Leiste). Als letztes
+        /// hinzugefügtes Top-Control belegt der MenuStrip die oberste Zeile über etwaigen ToolStrips.
+        /// </summary>
+        private void AttachWindowMenu(Form form, string currentViewId)
+        {
+            var menu = new MenuStrip { Dock = DockStyle.Top };
+            var fenster = new ToolStripMenuItem("Fenster");
+            menu.Items.Add(fenster);
+            PolyTrader.Core.Modularity.WindowMenu.Wire(fenster, this, currentViewId);
+            form.Controls.Add(menu);
+            form.MainMenuStrip = menu;
+        }
+
         public void ActivateMain()
         {
             if (_mainWindow == null || _mainWindow.IsDisposed) return;
@@ -61,6 +75,12 @@ namespace PolyTraderSharp.Ui
             if (string.IsNullOrEmpty(form.Text) || form.Text == form.Name)
                 form.Text = view.Title;
 
+            // Gemeinsames „Fenster"-Menü zentral in jedes Fenster injizieren (identische Shell-Chrome
+            // auf allen Fenstern; die inhaltlichen Controls bleiben designerbasiert). Nur, wenn das
+            // Fenster nicht bereits ein eigenes Menü mitbringt (z. B. der Launcher).
+            if (form.MainMenuStrip == null)
+                AttachWindowMenu(form, view.Id);
+
             // Alle Fenster maximiert (Vorgabe): Full-HD-Ziel, skaliert auf größere Auflösungen.
             form.StartPosition = FormStartPosition.CenterScreen;
             form.WindowState = FormWindowState.Maximized;
diff --git a/tests/PolyTrader.Tests/WindowMenuTests.cs b/tests/PolyTrader.Tests/WindowMenuTests.cs
new file mode 100644
index 0000000..236f6b5
--- /dev/null
+++ b/tests/PolyTrader.Tests/WindowMenuTests.cs
@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows.Forms;
+using PolyTrader.Core.Modularity;
+using Xunit;
+
+namespace PolyTrader.Tests
+{
+    /// <summary>Sicherheitsnetz für das gemeinsame „Fenster"-Menü (Slice 1): Inhalt + Verhalten.</summary>
+    public class WindowMenuTests
+    {
+        private sealed class FakeUiHost : IModuleUiHost
+        {
+            public List<ModuleView> ViewList { get; } = new();
+            public HashSet<string> OpenIds { get; } = new();
+            public List<string> Opened { get; } = new();
+            public bool MainActivated { get; private set; }
+
+            public IReadOnlyList<ModuleView> Views => ViewList;
+            public bool IsOpen(string viewId) => OpenIds.Contains(viewId);
+            public void OpenView(string viewId) => Opened.Add(viewId);
+            public void ActivateMain() => MainActivated = true;
+            public void RegisterView(ModuleView view) => ViewList.Add(view);
+            public event Action? OpenStateChanged { add { } remove { } }
+        }
+
+        private static FakeUiHost Host()
+        {
+            var h = new FakeUiHost();
+            h.RegisterView(new ModuleView { Id = "core.dashboard", Title = "Dashboard", Order = 1 });
+            h.RegisterView(new ModuleView { Id = "core.terminal", Title = "Terminal / Logs", Order = 2 });
+            h.OpenIds.Add("core.terminal");   // Terminal ist offen
+            return h;
+        }
+
+        [Fact]
+        public void Populate_lists_launcher_views_and_exit()
+        {
+            var host = Host();
+            var fenster = new ToolStripMenuItem("Fenster");
+
+            WindowMenu.Populate(fenster, host, currentViewId: "core.dashboard");
+
+            var texts = fenster.DropDownItems.OfType<ToolStripMenuItem>().Select(i => i.Text).ToList();
+            Assert.Equal("Launcher", texts[0]);
+            Assert.Contains("Dashboard", texts);
+            Assert.Contains("Terminal / Logs", texts);
+            Assert.Contains("Beenden", texts);
+        }
+
+        [Fact]
+        public void Current_view_is_bold_and_checked_open_view_is_checked()
+        {
+            var host = Host();
+            var fenster = new ToolStripMenuItem("Fenster");
+
+            WindowMenu.Populate(fenster, host, currentViewId: "core.dashboard");
+
+            var dashboard = fenster.DropDownItems.OfType<ToolStripMenuItem>().First(i => i.Text == "Dashboard");
+            var terminal = fenster.DropDownItems.OfType<ToolStripMenuItem>().First(i => i.Text == "Terminal / Logs");
+
+            Assert.True(dashboard.Checked);                 // aktuelles Fenster
+            Assert.True(dashboard.Font.Bold);
+            Assert.True(terminal.Checked);                  // offenes Fenster
+            Assert.False(terminal.Font.Bold);
+        }
+
+        [Fact]
+        public void Clicking_items_navigates()
+        {
+            var host = Host();
+            var fenster = new ToolStripMenuItem("Fenster");
+            WindowMenu.Populate(fenster, host, currentViewId: null);
+
+            var items = fenster.DropDownItems.OfType<ToolStripMenuItem>().ToList();
+            items.First(i => i.Text == "Launcher").PerformClick();
+            items.First(i => i.Text == "Terminal / Logs").PerformClick();
+
+            Assert.True(host.MainActivated);
+            Assert.Contains("core.terminal", host.Opened);
+        }
+    }
+}