diff --git a/desktop/src/main/python-manager.ts b/desktop/src/main/python-manager.ts
index 0cfe1884..33857f20 100644
--- a/desktop/src/main/python-manager.ts
+++ b/desktop/src/main/python-manager.ts
@@ -187,19 +187,17 @@ export class PythonBackend extends EventEmitter {
 
   private waitForReady(): Promise<void> {
     return new Promise((resolve) => {
-      const maxAttempts = 120
-      let attempts = 0
+      // Wall-clock deadline rather than an attempt counter: if the machine
+      // sleeps/suspends, the 1s timers stretch out and a counter would give up
+      // far too early. Time-based bounding tracks real elapsed time instead.
+      const timeoutMs = 120_000
+      const startedAt = Date.now()
 
       const check = () => {
-        attempts++
-        if (attempts % 10 === 0) {
-          this.emit('log', `Waiting for backend... (${attempts}s)`)
-        }
-
         const req = http.get(`http://127.0.0.1:${this.port}/config`, (res) => {
           if (res.statusCode === 200) {
             this.status = 'ready'
-            this.emit('log', `Backend ready on port ${this.port} after ${attempts}s`)
+            this.emit('log', `Backend ready on port ${this.port}`)
             this.emit('ready', this.port)
             resolve()
           } else {
@@ -215,13 +213,13 @@ export class PythonBackend extends EventEmitter {
       }
 
       const retry = () => {
-        if (this.status === 'stopped') {
+        if (this.status === 'stopped' || this.status === 'ready') {
           resolve()
           return
         }
-        if (attempts >= maxAttempts) {
+        if (Date.now() - startedAt >= timeoutMs) {
           this.status = 'error'
-          this.emit('error', `Backend failed to start within ${maxAttempts} seconds`)
+          this.emit('error', `Backend failed to start within ${Math.round(timeoutMs / 1000)} seconds`)
           resolve()
           return
         }
diff --git a/desktop/src/renderer/src/hooks/useBackend.ts b/desktop/src/renderer/src/hooks/useBackend.ts
index 5d002567..146ee071 100644
--- a/desktop/src/renderer/src/hooks/useBackend.ts
+++ b/desktop/src/renderer/src/hooks/useBackend.ts
@@ -24,29 +24,46 @@ export function useBackend() {
     }
   }, [])
 
+  // True once the backend has answered at least once. After this we never flip
+  // back to "error" from polling — a hidden/backgrounded window throttles JS
+  // timers, so attempt counters are unreliable and would otherwise produce a
+  // false "failed to start" even though the backend is alive.
+  const readyRef = useRef(false)
+  // Holds the latest resolved port so the visibility handler (registered once)
+  // always probes the correct port without re-running the effect.
+  const portRef = useRef(9899)
+
   useEffect(() => {
     let cancelled = false
     let offStatus: (() => void) | undefined
     const api = window.electronAPI
 
+    // Use a wall-clock deadline instead of an attempt counter so timer
+    // throttling (when the window is in the background) can't fast-forward us
+    // into a false failure. Only give up if we genuinely can't reach the
+    // backend for this long.
     const startPolling = async (port: number) => {
-      let attempts = 0
-      const maxAttempts = 90
+      portRef.current = port
+      const deadline = Date.now() + 90_000
 
       const poll = async () => {
         if (cancelled) return
-        attempts++
 
         const ready = await probeBackend(port)
         if (cancelled) return
 
         if (ready) {
+          readyRef.current = true
           setState({ status: 'ready', port })
           return
         }
 
-        if (attempts >= maxAttempts) {
-          setState({ status: 'error', port, error: 'Backend failed to start. Check if Python and dependencies are installed.' })
+        // Backend already answered before but is briefly unreachable (e.g.
+        // window was asleep): keep retrying, never surface an error.
+        if (!readyRef.current && Date.now() >= deadline) {
+          // Leave error undefined so StatusScreen shows the localized,
+          // user-friendly message instead of a raw technical string.
+          setState({ status: 'error', port })
           return
         }
 
@@ -59,31 +76,51 @@ export function useBackend() {
     if (api) {
       api.getBackendPort().then((port) => {
         const p = port || 9899
+        portRef.current = p
         setState((prev) => ({ ...prev, port: p }))
         startPolling(p)
       })
 
       offStatus = api.onBackendStatus((data) => {
         if (data.status === 'ready' && data.port) {
+          readyRef.current = true
+          portRef.current = data.port
           setState({ status: 'ready', port: data.port })
           if (pollingRef.current) {
             clearTimeout(pollingRef.current)
             pollingRef.current = null
           }
-        } else if (data.status === 'error') {
-          setState((prev) => ({ ...prev, status: 'error', error: data.error }))
+        } else if (data.status === 'error' && !readyRef.current) {
+          // Ignore late "error" from the main process once we've been ready —
+          // it usually means the window was backgrounded, not a real failure.
+          // Drop the raw technical message; StatusScreen shows a localized one.
+          setState((prev) => ({ ...prev, status: 'error' }))
         }
       })
     } else {
       startPolling(9899)
     }
 
+    // When the window comes back to the foreground, re-probe immediately so a
+    // user returning after a while sees the real (ready) state right away
+    // instead of waiting for the throttled timer to catch up.
+    const onVisible = () => {
+      if (cancelled || document.visibilityState !== 'visible') return
+      probeBackend(portRef.current).then((ready) => {
+        if (cancelled || !ready) return
+        readyRef.current = true
+        setState((prev) => ({ ...prev, status: 'ready' }))
+      })
+    }
+    document.addEventListener('visibilitychange', onVisible)
+
     return () => {
       cancelled = true
       if (pollingRef.current) {
         clearTimeout(pollingRef.current)
       }
       offStatus?.()
+      document.removeEventListener('visibilitychange', onVisible)
     }
   }, [probeBackend])
 
diff --git a/desktop/src/renderer/src/i18n.ts b/desktop/src/renderer/src/i18n.ts
index 3aa79317..3beb4ba3 100644
--- a/desktop/src/renderer/src/i18n.ts
+++ b/desktop/src/renderer/src/i18n.ts
@@ -290,9 +290,9 @@ const translations: Record<string, Record<string, string>> = {
     logs_live: '实时',
     logs_connecting: '日志流将在连接后显示...',
     status_starting: '正在启动 CowAgent...',
-    status_starting_desc: '正在初始化后端服务，请稍候',
-    status_error: '启动失败',
-    status_error_desc: '无法连接到后端服务',
+    status_starting_desc: '正在初始化客户端，请稍候',
+    status_error: '初始化失败',
+    status_error_desc: '客户端初始化失败，请重试',
     status_retry: '重试',
   },
   en: {
@@ -586,9 +586,9 @@ const translations: Record<string, Record<string, string>> = {
     logs_live: 'Live',
     logs_connecting: 'Log streaming will connect shortly...',
     status_starting: 'Starting CowAgent...',
-    status_starting_desc: 'Initializing the backend service, please wait',
-    status_error: 'Failed to Start',
-    status_error_desc: 'Unable to connect to the backend service',
+    status_starting_desc: 'Initializing the client, please wait',
+    status_error: 'Initialization Failed',
+    status_error_desc: 'Failed to initialize the client, please retry',
     status_retry: 'Retry',
   },
 }