diff --git a/main.js b/main.js
index 80f428c..f759b3f 100644
--- a/main.js
+++ b/main.js
@@ -4,7 +4,7 @@ const path = require('path');
 const packageJson = require('./package.json');
 
 const updateState = {
-    status: 'idle', // idle | checking | available | downloading | downloaded | not-available | error
+    status: 'idle', // idle | checking | available | downloading | downloaded | installing | not-available | error
     info: null,
     error: null,
 };
@@ -24,6 +24,7 @@ function isNewerVersionAvailable(info) {
 }
 
 let updateCheckInProgress = false;
+let installInProgress = false;
 
 function resolveBackendUrl() {
     const configuredUrl = (process.env.CHATTZ_URL || process.env.APP_BASE_URL || '').trim();
@@ -49,6 +50,10 @@ function webContentsOrigin(webContents) {
 }
 
 async function runUpdateCheck(reason = 'manual') {
+    if (installInProgress) {
+        console.log(`Update check skipped (${reason}): install already in progress`);
+        return;
+    }
     if (updateCheckInProgress) {
         console.log(`Update check skipped (${reason}): another check is already in progress`);
         return;
@@ -78,6 +83,47 @@ async function runUpdateCheck(reason = 'manual') {
     }
 }
 
+function installDownloadedUpdate() {
+    if (installInProgress) {
+        console.log('Update install already in progress');
+        return;
+    }
+
+    installInProgress = true;
+    updateState.status = 'installing';
+    updateState.error = null;
+    broadcastUpdateState();
+
+    const wins = BrowserWindow.getAllWindows();
+    for (const win of wins) {
+        if (win.isDestroyed()) continue;
+        try {
+            win.removeAllListeners('close');
+            win.destroy();
+        } catch (err) {
+            console.warn('Failed to destroy window before update install', err);
+        }
+    }
+
+    setImmediate(() => {
+        try {
+            autoUpdater.quitAndInstall(false, true);
+        } catch (err) {
+            installInProgress = false;
+            updateState.status = 'error';
+            updateState.error = err && err.message ? err.message : String(err);
+            broadcastUpdateState();
+            console.error('quitAndInstall failed', err);
+        }
+    });
+
+    setTimeout(() => {
+        if (installInProgress) {
+            console.warn('Update install is still waiting for app shutdown');
+        }
+    }, 15000);
+}
+
 function createWindow() {
     const sess = session.fromPartition('persist:chattz');
     const backendUrl = resolveBackendUrl();
@@ -209,6 +255,7 @@ app.whenReady().then(() => {
     });
 
     ipcMain.on('download-update', () => {
+        if (installInProgress) return;
         updateState.status = 'downloading';
         updateState.error = null;
         broadcastUpdateState();
@@ -216,7 +263,7 @@ app.whenReady().then(() => {
     });
 
     ipcMain.on('quit-and-install', () => {
-        autoUpdater.quitAndInstall();
+        installDownloadedUpdate();
     });
 
     // Check once on startup