diff --git a/packages/electron/main.mjs b/packages/electron/main.mjs
index 2c51c1b8..1ea1100c 100644
--- a/packages/electron/main.mjs
+++ b/packages/electron/main.mjs
@@ -2101,7 +2101,9 @@ const createMiniChatWindow = async ({ mode, sessionId = '', directory = '', proj
     icon: getWindowIconPath(),
     show: false,
     backgroundColor: '#151313',
-    titleBarStyle: process.platform === 'darwin' ? 'hidden' : 'default',
+    frame: process.platform === 'win32' ? false : undefined,
+    autoHideMenuBar: process.platform !== 'darwin',
+    titleBarStyle: process.platform === 'darwin' || process.platform === 'win32' ? 'hidden' : 'default',
     trafficLightPosition: process.platform === 'darwin' ? { x: 16, y: 17 } : undefined,
     webPreferences: {
       additionalArguments: [
diff --git a/packages/ui/src/components/desktop/WindowsWindowControls.tsx b/packages/ui/src/components/desktop/WindowsWindowControls.tsx
new file mode 100644
index 00000000..153850cb
--- /dev/null
+++ b/packages/ui/src/components/desktop/WindowsWindowControls.tsx
@@ -0,0 +1,83 @@
+import React, { useEffect } from 'react';
+
+import { Icon } from '@/components/icon/Icon';
+import { useI18n } from '@/lib/i18n';
+import { cn } from '@/lib/utils';
+import { invokeDesktop } from '@/lib/desktop';
+
+type WindowsWindowControlsProps = {
+  visible: boolean;
+};
+
+export const WindowsWindowControls = React.memo(function WindowsWindowControls({ visible }: WindowsWindowControlsProps) {
+  const { t } = useI18n();
+  const [isMaximized, setIsMaximized] = React.useState(false);
+
+  useEffect(() => {
+    if (!visible) {
+      return;
+    }
+
+    let disposed = false;
+    void invokeDesktop<{ maximized?: boolean }>('desktop_get_current_window_state')
+      .then((state) => {
+        if (!disposed) {
+          setIsMaximized(Boolean(state?.maximized));
+        }
+      })
+      .catch(() => {});
+
+    const handleMaximizedChange = (event: Event) => {
+      const detail = (event as CustomEvent<{ maximized?: boolean }>).detail;
+      setIsMaximized(Boolean(detail?.maximized));
+    };
+
+    window.addEventListener('openchamber:window-maximized-changed', handleMaximizedChange);
+    return () => {
+      disposed = true;
+      window.removeEventListener('openchamber:window-maximized-changed', handleMaximizedChange);
+    };
+  }, [visible]);
+
+  if (!visible) {
+    return null;
+  }
+
+  const buttonClassName = 'app-region-no-drag inline-flex h-12 w-11 items-center justify-center text-muted-foreground transition-colors hover:bg-interactive-hover hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary';
+
+  return (
+    <div className="app-region-no-drag -mr-3 ml-2 flex h-12 shrink-0 items-center" aria-label={t('header.windowControls.groupAria')}>
+      <button
+        type="button"
+        className={buttonClassName}
+        onClick={() => { void invokeDesktop('desktop_minimize_current_window'); }}
+        title={t('header.windowControls.minimize')}
+        aria-label={t('header.windowControls.minimize')}
+      >
+        <Icon name="subtract" className="h-4 w-4" />
+      </button>
+      <button
+        type="button"
+        className={buttonClassName}
+        onClick={() => {
+          void invokeDesktop<{ maximized?: boolean }>('desktop_toggle_current_window_maximized')
+            .then((state) => setIsMaximized(Boolean(state?.maximized)))
+            .catch(() => {});
+        }}
+        title={isMaximized ? t('header.windowControls.restore') : t('header.windowControls.maximize')}
+        aria-label={isMaximized ? t('header.windowControls.restore') : t('header.windowControls.maximize')}
+      >
+        <Icon name={isMaximized ? 'fullscreen-exit' : 'checkbox-blank'} className="h-3.5 w-3.5" />
+      </button>
+      <button
+        type="button"
+        className={cn(buttonClassName, 'hover:bg-status-error hover:text-status-error-foreground')}
+        onClick={() => { void invokeDesktop('desktop_close_current_window'); }}
+        title={t('header.windowControls.close')}
+        aria-label={t('header.windowControls.close')}
+      >
+        <Icon name="close" className="h-4 w-4" />
+      </button>
+    </div>
+  );
+});
diff --git a/packages/ui/src/components/layout/Header.tsx b/packages/ui/src/components/layout/Header.tsx
index 2c3b850d..67bce021 100644
--- a/packages/ui/src/components/layout/Header.tsx
+++ b/packages/ui/src/components/layout/Header.tsx
@@ -32,6 +32,7 @@ import { useFeatureFlagsStore } from '@/stores/useFeatureFlagsStore';
 import { useGitHubAuthStore } from '@/stores/useGitHubAuthStore';
 import { useRuntimeAPIs } from '@/hooks/useRuntimeAPIs';
 import { ContextUsageDisplay } from '@/components/ui/ContextUsageDisplay';
+import { WindowsWindowControls } from '@/components/desktop/WindowsWindowControls';
 import { UpdateDialog } from '@/components/ui/UpdateDialog';
 import { useDeviceInfo, useTabletStandalonePwaRuntime } from '@/lib/device';
 import { cn, hasModifier } from '@/lib/utils';
@@ -127,83 +128,6 @@ const HeaderIconActionButton = React.memo(function HeaderIconActionButton({
   );
 });
 
-type WindowsWindowControlsProps = {
-  visible: boolean;
-};
-
-const WindowsWindowControls = React.memo(function WindowsWindowControls({ visible }: WindowsWindowControlsProps) {
-  const { t } = useI18n();
-  const [isMaximized, setIsMaximized] = React.useState(false);
-
-  useEffect(() => {
-    if (!visible) {
-      return;
-    }
-
-    let disposed = false;
-    void invokeDesktop<{ maximized?: boolean }>('desktop_get_current_window_state')
-      .then((state) => {
-        if (!disposed) {
-          setIsMaximized(Boolean(state?.maximized));
-        }
-      })
-      .catch(() => {});
-
-    const handleMaximizedChange = (event: Event) => {
-      const detail = (event as CustomEvent<{ maximized?: boolean }>).detail;
-      setIsMaximized(Boolean(detail?.maximized));
-    };
-
-    window.addEventListener('openchamber:window-maximized-changed', handleMaximizedChange);
-    return () => {
-      disposed = true;
-      window.removeEventListener('openchamber:window-maximized-changed', handleMaximizedChange);
-    };
-  }, [visible]);
-
-  if (!visible) {
-    return null;
-  }
-
-  const buttonClassName = 'app-region-no-drag inline-flex h-12 w-11 items-center justify-center text-muted-foreground transition-colors hover:bg-interactive-hover hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary';
-
-  return (
-    <div className="app-region-no-drag -mr-3 ml-2 flex h-12 shrink-0 items-center" aria-label={t('header.windowControls.groupAria')}>
-      <button
-        type="button"
-        className={buttonClassName}
-        onClick={() => { void invokeDesktop('desktop_minimize_current_window'); }}
-        title={t('header.windowControls.minimize')}
-        aria-label={t('header.windowControls.minimize')}
-      >
-        <Icon name="subtract" className="h-4 w-4" />
-      </button>
-      <button
-        type="button"
-        className={buttonClassName}
-        onClick={() => {
-          void invokeDesktop<{ maximized?: boolean }>('desktop_toggle_current_window_maximized')
-            .then((state) => setIsMaximized(Boolean(state?.maximized)))
-            .catch(() => {});
-        }}
-        title={isMaximized ? t('header.windowControls.restore') : t('header.windowControls.maximize')}
-        aria-label={isMaximized ? t('header.windowControls.restore') : t('header.windowControls.maximize')}
-      >
-        <Icon name={isMaximized ? 'fullscreen-exit' : 'checkbox-blank'} className="h-3.5 w-3.5" />
-      </button>
-      <button
-        type="button"
-        className={cn(buttonClassName, 'hover:bg-status-error hover:text-status-error-foreground')}
-        onClick={() => { void invokeDesktop('desktop_close_current_window'); }}
-        title={t('header.windowControls.close')}
-        aria-label={t('header.windowControls.close')}
-      >
-        <Icon name="close" className="h-4 w-4" />
-      </button>
-    </div>
-  );
-});
-
 type DesktopGitHubControlProps = {
   isMobile: boolean;
   githubAuthStatus: GitHubAuthStatus | null;
diff --git a/packages/ui/src/components/mini-chat/MiniChatLayout.tsx b/packages/ui/src/components/mini-chat/MiniChatLayout.tsx
index 5d5002c2..bff69eb7 100644
--- a/packages/ui/src/components/mini-chat/MiniChatLayout.tsx
+++ b/packages/ui/src/components/mini-chat/MiniChatLayout.tsx
@@ -3,6 +3,7 @@ import { Button } from '@/components/ui/button';
 import { ChatContainer } from '@/components/chat/ChatContainer';
 import { ChatSurfaceProvider } from '@/components/chat/ChatSurfaceContext';
 import { ContextUsageDisplay } from '@/components/ui/ContextUsageDisplay';
+import { WindowsWindowControls } from '@/components/desktop/WindowsWindowControls';
 import { SessionSwitcherDropdown } from '@/components/session/SessionSwitcherDropdown';
 import { cn } from '@/lib/utils';
 import { useI18n } from '@/lib/i18n';
@@ -69,6 +70,9 @@ const MiniChatHeader: React.FC<{ mode: MiniChatMode }> = ({ mode }) => {
   const [pinned, setPinned] = React.useState(false);
   const macosMajor = typeof window !== 'undefined' ? window.__OPENCHAMBER_MACOS_MAJOR__ ?? 0 : 0;
   const hasMacTrafficLights = Number.isFinite(macosMajor) && macosMajor > 0;
+  const isWindowsElectronDesktop = typeof window !== 'undefined'
+    && Boolean(window.__OPENCHAMBER_ELECTRON__)
+    && window.__OPENCHAMBER_PLATFORM__ === 'win32';
   const macosHeaderSizeClass = hasMacTrafficLights
     ? macosMajor >= 26
       ? 'h-12'
@@ -258,7 +262,7 @@ const MiniChatHeader: React.FC<{ mode: MiniChatMode }> = ({ mode }) => {
       className={cn(
         'flex items-center gap-3 border-b border-[var(--interactive-border)] bg-sidebar pr-3',
         hasMacTrafficLights ? 'pl-[5.5rem]' : 'pl-3',
-        macosHeaderSizeClass || 'min-h-14',
+        isWindowsElectronDesktop ? 'h-12' : macosHeaderSizeClass || 'min-h-14',
       )}
       style={dragRegionStyle}
     >
@@ -327,6 +331,7 @@ const MiniChatHeader: React.FC<{ mode: MiniChatMode }> = ({ mode }) => {
       >
         <Icon name="external-link" className="h-4 w-4" />
       </Button>
+      <WindowsWindowControls visible={isWindowsElectronDesktop} />
     </header>
   );
 };