diff --git a/apps/desktop/e2e/boot-failure.spec.ts b/apps/desktop/e2e/boot-failure.spec.ts
index 91433c3ccc89..4f316d356c6f 100644
--- a/apps/desktop/e2e/boot-failure.spec.ts
+++ b/apps/desktop/e2e/boot-failure.spec.ts
@@ -1,11 +1,11 @@
 /**
  * E2E boot-failure tests — verify the app shows an error overlay when the
- * backend can't reach the inference provider.
+ * backend can't start.
  *
- * Launches the app with a provider pointing at a dead endpoint (port 1).
- * The `hermes serve` backend starts, but when the renderer tries to connect
- * or when a runtime check fails, the app should show a boot failure or
- * onboarding error overlay.
+ * Injects a fake boot error (HERMES_DESKTOP_BOOT_FAKE_ERROR) so the backend
+ * resolution fails with a controlled error message. The app should show the
+ * BootFailureOverlay with retry/repair actions — no progress bar should be
+ * visible.
  *
  * Prerequisite: `npm run build` must have been run so dist/ exists.
  */
@@ -26,17 +26,13 @@ test.afterAll(async () => {
   fixture = null
 })
 
-test.describe('boot failure with dead provider endpoint', () => {
-  test('app shows error state or onboarding', async () => {
-    fixture = await setupDeadBackend()
+test.describe('boot failure with dead backend', () => {
+  test('app shows error state', async () => {
+    // Inject a fake boot error so the backend resolution "fails" with a
+    // controlled error message. This is the only reliable way to trigger
+    // BootFailureOverlay in dev mode.
+    fixture = await setupDeadBackend({ fakeError: true })
 
-    // With a dead provider endpoint, the app should eventually show either:
-    //  1. A boot failure overlay (if the backend fails to start), or
-    //  2. An onboarding overlay with an error (if the runtime check fails)
-    // Both outcomes prove the app is handling provider failures gracefully.
-    //
-    // We give it a generous timeout — the backend needs to start, the
-    // renderer needs to boot, and then the runtime check needs to fail.
     await waitForBootFailure(fixture.page, 90_000)
   })
 
diff --git a/apps/desktop/e2e/fixtures.ts b/apps/desktop/e2e/fixtures.ts
index 14da89a3af1e..aa8dd94d2518 100644
--- a/apps/desktop/e2e/fixtures.ts
+++ b/apps/desktop/e2e/fixtures.ts
@@ -387,12 +387,24 @@ export interface DeadBackendFixture {
   cleanup: () => Promise<void>
 }
 
+export interface DeadBackendOptions {
+  /**
+   * When true, inject a fake boot error via HERMES_DESKTOP_BOOT_FAKE_ERROR
+   * so the backend resolution itself "fails" with a controlled error message.
+   * This is the only reliable way to trigger BootFailureOverlay in dev mode
+   * (the real backend always resolves via SOURCE_REPO_ROOT).
+   */
+  fakeError?: boolean
+}
+
 /**
  * Launch the app with a provider pointing at a dead endpoint (port 1, which
- * nothing listens on). The boot should fail with a connection error,
- * triggering the BootFailureOverlay.
+ * nothing listens on). By default the backend still boots (`hermes serve`
+ * starts fine — the dead endpoint only matters at chat time). Pass
+ * `{ fakeError: true }` to inject a fake boot failure, triggering the
+ * BootFailureOverlay.
  */
-export async function setupDeadBackend(): Promise<DeadBackendFixture> {
+export async function setupDeadBackend(options: DeadBackendOptions = {}): Promise<DeadBackendFixture> {
   const sandbox = createSandbox('dead')
   const configPath = path.join(sandbox.hermesHome, 'config.yaml')
   fs.writeFileSync(
@@ -415,7 +427,7 @@ providers:
   )
   writeEnvFile(sandbox.hermesHome)
 
-  const env = buildAppEnv(sandbox)
+  const env = buildAppEnv(sandbox, options.fakeError ? { HERMES_DESKTOP_BOOT_FAKE_ERROR: 'Failed to connect to Hermes backend: connection refused' } : {})
   const { app, page } = await launchDesktop(env)
 
   return {
@@ -636,25 +648,32 @@ export async function waitForOnboarding(page: Page, timeoutMs = 60_000): Promise
 export async function waitForBootFailure(page: Page, timeoutMs = 60_000): Promise<void> {
   await page.waitForFunction(
     () => {
-      const root = document.getElementById('root')
+      // Boot failure is terminal: the backend gave up. The renderer shows
+      // either BootFailureOverlay (z-1400, with Retry/Repair buttons) or
+      // falls back to the onboarding picker (z-1300) as a recovery path.
+      // Either way, no progress bar should be visible and an error must
+      // have surfaced (toast, boot-failure banner, or the overlay itself).
+      const hasProgressBar = Boolean(
+        document.querySelector('[role="progressbar"], .h-2.rounded-full.bg-muted')
+      )
 
-      if (!root) {
+      if (hasProgressBar) {
         return false
       }
 
-      const text = root.textContent ?? ''
+      const text = document.body.textContent ?? ''
 
-      // A dead provider either produces a boot failure or falls back to the
-      // provider onboarding screen after the runtime check fails.
-      return (
-        text.includes('error') ||
-        text.includes('Error') ||
-        text.includes('failed') ||
-        text.includes('Failed') ||
+      // BootFailureOverlay buttons.
+      const hasFailureUI =
         text.includes('Retry') ||
         text.includes('Repair') ||
-        text.includes("Let's get you setup")
-      )
+        text.includes('Use local gateway') ||
+        text.includes('Connection settings')
+
+      // The error toast / notification that fires on failDesktopBoot().
+      const hasErrorToast = text.includes('Desktop boot failed')
+
+      return hasFailureUI || hasErrorToast
     },
     undefined,
     { timeout: timeoutMs },
diff --git a/apps/desktop/electron/main.ts b/apps/desktop/electron/main.ts
index 517121c2061d..fb60adbf1bf9 100644
--- a/apps/desktop/electron/main.ts
+++ b/apps/desktop/electron/main.ts
@@ -542,6 +542,7 @@ const DESKTOP_LOG_BACKUP_COUNT = 3
 const DESKTOP_LOG_DISCARD_BYTES = DESKTOP_LOG_MAX_BYTES * 4
 const desktopLogBackupPath = n => `${DESKTOP_LOG_PATH}.${n}`
 const BOOT_FAKE_MODE = process.env.HERMES_DESKTOP_BOOT_FAKE === '1'
+const BOOT_FAKE_ERROR = process.env.HERMES_DESKTOP_BOOT_FAKE_ERROR || ''
 
 const BOOT_FAKE_STEP_MS = (() => {
   const raw = Number.parseInt(String(process.env.HERMES_DESKTOP_BOOT_FAKE_STEP_MS || ''), 10)
@@ -6999,6 +7000,16 @@ async function startHermes() {
     throw backendStartFailure
   }
 
+  // E2E: simulate a boot failure without breaking the real backend. The boot
+  // progresses a few steps, then fails with the given error message.
+  if (BOOT_FAKE_ERROR) {
+    await advanceBootProgress('backend.resolve', 'Resolving Hermes backend', 8)
+    const error = new Error(BOOT_FAKE_ERROR) as any
+    error.isBootstrapFailure = true
+    bootstrapFailure = error
+    throw error
+  }
+
   const existingConnectionPromise = backendConnectionState.getPromise()
 
   if (existingConnectionPromise) {
diff --git a/apps/desktop/src/components/onboarding/index.tsx b/apps/desktop/src/components/onboarding/index.tsx
index 87cc31648474..900d3f0c8739 100644
--- a/apps/desktop/src/components/onboarding/index.tsx
+++ b/apps/desktop/src/components/onboarding/index.tsx
@@ -355,9 +355,15 @@ function ReasonNotice({ reason }: { reason: string }) {
 function Preparing({ boot }: { boot: DesktopBootState }) {
   const { t } = useI18n()
   const progress = Math.max(2, Math.min(100, Math.round(boot.progress)))
-  const hasError = Boolean(boot.error)
   const installing = boot.phase.startsWith('runtime.')
 
+  // When boot fails, BootFailureOverlay (z-1400) owns the screen. Bail out
+  // here so we never paint a progress bar alongside the error overlay —
+  // E2E screenshots can catch the two mid-transition.
+  if (boot.error) {
+    return null
+  }
+
   return (
     <div className="grid gap-3" role="status">
       <p className="text-sm text-muted-foreground">
@@ -365,10 +371,7 @@ function Preparing({ boot }: { boot: DesktopBootState }) {
       </p>
       <div className="h-2 overflow-hidden rounded-full bg-muted">
         <div
-          className={cn(
-            'h-full rounded-full bg-primary transition-[width] duration-300 ease-out',
-            hasError && 'bg-destructive'
-          )}
+          className="h-full rounded-full bg-primary transition-[width] duration-300 ease-out"
           style={{ width: `${progress}%` }}
         />
       </div>
@@ -376,7 +379,6 @@ function Preparing({ boot }: { boot: DesktopBootState }) {
         <span className="truncate">{boot.message}</span>
         <span>{progress}%</span>
       </div>
-      {hasError ? <p className="text-xs text-destructive">{boot.error}</p> : null}
     </div>
   )
 }
diff --git a/apps/desktop/src/store/boot.ts b/apps/desktop/src/store/boot.ts
index f25be5089db4..5300bdfc7d9a 100644
--- a/apps/desktop/src/store/boot.ts
+++ b/apps/desktop/src/store/boot.ts
@@ -33,12 +33,16 @@ export function applyDesktopBootProgress(progress: DesktopBootProgress) {
   const nextProgress = clampProgress(progress.progress)
   const mergedProgress = progress.running ? Math.max(current.progress, nextProgress) : nextProgress
 
+  // Don't let a late progress event (error: null) clobber a previously-set
+  // boot failure — failDesktopBoot is terminal for this boot cycle.
+  const error = progress.error ?? (current.running ? null : current.error)
+
   $desktopBoot.set({
     ...current,
     ...progress,
-    error: progress.error ?? null,
+    error,
     progress: mergedProgress,
-    visible: progress.running || mergedProgress < 100 || Boolean(progress.error)
+    visible: progress.running || mergedProgress < 100 || Boolean(error)
   })
 }