diff --git a/desktop/src/main/index.ts b/desktop/src/main/index.ts
index d47052d4..5f9d1301 100644
--- a/desktop/src/main/index.ts
+++ b/desktop/src/main/index.ts
@@ -253,7 +253,14 @@ function setupIPC() {
     setUpdateLanguage(lang)
     startDownload()
   })
-  ipcMain.handle('update-install', () => quitAndInstall())
+  ipcMain.handle('update-install', () => {
+    // Let the window actually close so the app can fully quit — otherwise the
+    // close-to-tray handler preventDefault()s it, the process stays alive, and
+    // Squirrel.Mac can't swap the app bundle (the update silently no-ops and
+    // relaunching still shows the old version).
+    isQuitting = true
+    quitAndInstall()
+  })
 
   // Synchronous OS locale lookup (e.g. "zh-CN", "en-US"). Used by the renderer
   // to pick a sensible default UI language on first run before any paint.
diff --git a/desktop/src/main/updater.ts b/desktop/src/main/updater.ts
index 048e165a..ff286e73 100644
--- a/desktop/src/main/updater.ts
+++ b/desktop/src/main/updater.ts
@@ -229,6 +229,16 @@ function attemptDownload(): void {
 export function quitAndInstall(): void {
   if (!app.isPackaged) return
   log('quitAndInstall: relaunching to install update')
-  // isSilent=false (show installer), isForceRunAfter=true (relaunch after).
-  autoUpdater.quitAndInstall(false, true)
+  // isSilent MUST be true on Windows: our NSIS installer is an "assisted"
+  // installer (oneClick:false + allowToChangeInstallationDirectory), so a
+  // non-silent update re-shows the install-dir / install-mode wizard instead of
+  // updating in place. Silent skips the wizard and updates directly. macOS
+  // (Squirrel.Mac) ignores isSilent, so false there is fine.
+  // isForceRunAfter=true relaunches the app once the install finishes.
+  // Drop window-all-closed handlers first: with an assisted NSIS installer a
+  // lingering handler can keep the process alive and stop the installer from
+  // replacing files / relaunching (a documented electron-updater gotcha).
+  app.removeAllListeners('window-all-closed')
+  const isSilent = process.platform === 'win32'
+  autoUpdater.quitAndInstall(isSilent, true)
 }
diff --git a/desktop/src/renderer/src/components/UpdateBanner.tsx b/desktop/src/renderer/src/components/UpdateBanner.tsx
index b51d1e8b..bdd45aff 100644
--- a/desktop/src/renderer/src/components/UpdateBanner.tsx
+++ b/desktop/src/renderer/src/components/UpdateBanner.tsx
@@ -1,5 +1,5 @@
 import React from 'react'
-import { Download, RefreshCw, X, Loader2 } from 'lucide-react'
+import { Download, RefreshCw, X, Loader2, AlertTriangle } from 'lucide-react'
 import { t } from '../i18n'
 import { useUpdateStore, hasAvailableUpdate } from '../store/updateStore'
 
@@ -12,9 +12,12 @@ const UpdateBanner: React.FC = () => {
 
   const available = hasAvailableUpdate(state)
   const status = state.status
+  const errored = status?.state === 'error'
 
-  // Render nothing when there's no update, or the panel is closed (dismissed).
-  if (!available || !open) return null
+  // Show the panel when it's open AND we either know of an update or hit an
+  // error. Keeping it up on error is important: a failed download must surface
+  // a visible message instead of silently doing nothing.
+  if (!open || (!available && !errored)) return null
 
   const version = state.version
   const downloading = status?.state === 'downloading'
@@ -25,8 +28,12 @@ const UpdateBanner: React.FC = () => {
       <div className="rounded-lg border border-default bg-elevated shadow-lg p-3 space-y-2.5">
         <div className="flex items-start justify-between gap-2">
           <div className="min-w-0">
-            <p className="text-[13px] font-semibold text-content">{t('update_available')}</p>
-            {version && <p className="text-xs text-content-tertiary mt-0.5">v{version}</p>}
+            <p className="text-[13px] font-semibold text-content">
+              {errored ? t('update_failed') : t('update_available')}
+            </p>
+            {!errored && version && (
+              <p className="text-xs text-content-tertiary mt-0.5">v{version}</p>
+            )}
           </div>
           <button
             onClick={() => state.dismiss()}
@@ -37,7 +44,25 @@ const UpdateBanner: React.FC = () => {
           </button>
         </div>
 
-          {downloading && (
+          {errored && (
+            <div className="space-y-2.5">
+              <div className="flex items-start gap-2 text-xs text-content-secondary">
+                <AlertTriangle size={13} className="text-amber-500 flex-shrink-0 mt-0.5" />
+                <span className="break-words">
+                  {status?.state === 'error' ? status.message : ''}
+                </span>
+              </div>
+              <button
+                onClick={() => state.download()}
+                className="w-full inline-flex items-center justify-center gap-2 rounded-btn bg-accent text-accent-contrast hover:bg-accent-hover px-3 py-2 text-[13px] font-medium cursor-pointer transition-colors"
+              >
+                <RefreshCw size={15} />
+                {t('update_retry')}
+              </button>
+            </div>
+          )}
+
+          {!errored && downloading && (
             <div className="space-y-1">
               <div className="flex items-center gap-2 text-xs text-content-secondary">
                 <Loader2 size={13} className="animate-spin" />
@@ -49,7 +74,7 @@ const UpdateBanner: React.FC = () => {
             </div>
           )}
 
-          {!downloading && !downloaded && (
+          {!errored && !downloading && !downloaded && (
             <button
               onClick={() => state.download()}
               className="w-full inline-flex items-center justify-center gap-2 rounded-btn bg-accent text-accent-contrast hover:bg-accent-hover px-3 py-2 text-[13px] font-medium cursor-pointer transition-colors"
@@ -59,7 +84,7 @@ const UpdateBanner: React.FC = () => {
             </button>
           )}
 
-          {downloaded && (
+          {!errored && downloaded && (
             <button
               onClick={() => state.install()}
               className="w-full inline-flex items-center justify-center gap-2 rounded-btn bg-accent text-accent-contrast hover:bg-accent-hover px-3 py-2 text-[13px] font-medium cursor-pointer transition-colors"
diff --git a/desktop/src/renderer/src/i18n.ts b/desktop/src/renderer/src/i18n.ts
index e0b45601..ade035f9 100644
--- a/desktop/src/renderer/src/i18n.ts
+++ b/desktop/src/renderer/src/i18n.ts
@@ -77,6 +77,8 @@ const translations: Record<string, Record<string, string>> = {
     update_latest: '已是最新版本',
     update_check: '检查更新',
     update_checking: '正在检查…',
+    update_failed: '更新失败',
+    update_retry: '重试',
     menu_more: '更多',
     menu_theme_light: '浅色模式',
     menu_theme_dark: '深色模式',
@@ -447,6 +449,8 @@ const translations: Record<string, Record<string, string>> = {
     update_latest: 'You are up to date',
     update_check: 'Check for updates',
     update_checking: 'Checking…',
+    update_failed: 'Update failed',
+    update_retry: 'Retry',
     menu_more: 'More',
     menu_theme_light: 'Light mode',
     menu_theme_dark: 'Dark mode',
diff --git a/desktop/src/renderer/src/store/updateStore.ts b/desktop/src/renderer/src/store/updateStore.ts
index a64a5eb5..2ac4b48c 100644
--- a/desktop/src/renderer/src/store/updateStore.ts
+++ b/desktop/src/renderer/src/store/updateStore.ts
@@ -50,13 +50,11 @@ export const useUpdateStore = create<UpdateState>((set, get) => ({
   closePanel: () => set({ panelOpen: false }),
 
   recheck: () => {
-    const st = get()
-    // If we already know about an available/downloaded update, just re-open the
-    // panel (clearing the dismiss for this version) instead of waiting on a
-    // network round-trip — the user asked to see it.
-    if (hasAvailableUpdate(st)) {
-      set({ dismissedVersion: null, panelOpen: true })
-    }
+    // Open the panel and clear any dismiss so the result of this explicit check
+    // is always visible — available, error, or (via the menu label) up-to-date.
+    // Previously the panel only opened when an update was already known, so a
+    // download/check error rendered nothing and looked like a dead click.
+    set({ dismissedVersion: null, panelOpen: true })
     // Always kick a fresh check too (picks up newer versions / recovers errors).
     // Pass the UI language so downloads route to the China CDN / R2 accordingly.
     window.electronAPI?.checkForUpdate?.(getLang())