diff --git a/src/desktop/winappupdate.js b/src/desktop/winappupdate.js
index a5b3462..295ffff 100644
--- a/src/desktop/winappupdate.js
+++ b/src/desktop/winappupdate.js
@@ -126,13 +126,14 @@ export const prepareInstallerPath = async (installerPath) => {
 const startWindowsInstallerProgressWatch = (
   logPath,
   sendProgress,
-  onInstallSuccessful
+  { onInstallSuccessful, onInstallFailed, onStalled, stallTimeoutMs }
 ) => {
   let installerOutput = ''
   let offset = 0
   let lastPercent = null
   let lastMessage = null
-  let installSuccessNotified = false
+  let outcomeNotified = false
+  let lastActivityAt = Date.now()
 
   const poll = async () => {
     try {
@@ -145,6 +146,7 @@ const startWindowsInstallerProgressWatch = (
         await handle.read(buffer, 0, buffer.length, offset)
         offset = stat.size
         installerOutput += buffer.toString('utf8')
+        lastActivityAt = Date.now()
 
         const { percent, message } =
           parseWindowsInstallerProgress(installerOutput)
@@ -160,13 +162,14 @@ const startWindowsInstallerProgressWatch = (
           })
         }
 
-        if (
-          !installSuccessNotified &&
-          isWindowsInstallSuccessful(installerOutput) &&
-          !isWindowsInstallFailed(installerOutput)
-        ) {
-          installSuccessNotified = true
-          onInstallSuccessful?.(installerOutput)
+        if (!outcomeNotified) {
+          if (isWindowsInstallFailed(installerOutput)) {
+            outcomeNotified = true
+            onInstallFailed?.(installerOutput)
+          } else if (isWindowsInstallSuccessful(installerOutput)) {
+            outcomeNotified = true
+            onInstallSuccessful?.(installerOutput)
+          }
         }
       } finally {
         await handle.close()
@@ -179,6 +182,18 @@ const startWindowsInstallerProgressWatch = (
   }
 
   const intervalId = setInterval(() => {
+    // The installer runs detached (outside our job object), so a dead
+    // installer only shows up as the log going quiet before any outcome.
+    if (
+      !outcomeNotified &&
+      stallTimeoutMs > 0 &&
+      Date.now() - lastActivityAt > stallTimeoutMs
+    ) {
+      outcomeNotified = true
+      onStalled?.(installerOutput)
+      return
+    }
+
     poll().catch((error) => {
       console.error('[app-update] installer log poll error:', error)
     })
@@ -249,8 +264,22 @@ export const launchWindowsInstaller = async (
     const stopProgressWatch = startWindowsInstallerProgressWatch(
       logPath,
       sendProgress,
-      (output) => {
-        settleSuccess(output)
+      {
+        stallTimeoutMs: 3 * 60 * 1000,
+        onInstallSuccessful: (output) => {
+          settleSuccess(output)
+        },
+        onInstallFailed: (output) => {
+          settleFailure(getInstallErrorMessage(null, output))
+        },
+        onStalled: (output) => {
+          settleFailure(
+            getInstallErrorMessage(
+              new Error('The update installer stopped responding.'),
+              output
+            )
+          )
+        }
       }
     )
 
@@ -258,65 +287,63 @@ export const launchWindowsInstaller = async (
       return await stopProgressWatch()
     }
 
-    // Silent NSIS install in a detached child process (not a batch file).
+    // Silent NSIS install.
     // /S = silent (https://nsis.sourceforge.io/Reference/SilentInstall)
     // /UPDATE = in-app update (stage into Farm Control.new; swap after exit)
     // /RESTARTFC = installer waits for this process to exit, swaps folders, relaunches
     // /PARENTPID = exact process to wait for (CEF may outlive the launcher)
-    // /LOG= + FARMCONTROL_INSTALL_LOG = progress log
-    // (installer:% / PHASE / STATUS / COPY_TOTAL / COPY_FILE)
-    const installerArgs = [
+    // /LOG= = progress log (installer:% / PHASE / STATUS / COPY_TOTAL / COPY_FILE)
+    const installerCommandLine = [
+      `"${resolvedPath}"`,
       '/S',
       '/UPDATE',
       '/RESTARTFC',
       `/PARENTPID=${process.pid}`,
-      `/LOG=${logPath}`
-    ]
+      `/LOG="${logPath}"`
+    ].join(' ')
 
-    const installerProcess = spawn(resolvedPath, installerArgs, {
-      detached: true,
-      env: {
-        ...process.env,
-        FARMCONTROL_INSTALL_LOG: logPath
-      },
-      stdio: 'ignore',
-      windowsHide: true
-    })
+    // This process runs inside a Windows job object (CEF/launcher) that kills
+    // every child process when the app exits — a directly spawned installer
+    // (even with detached: true) inherits the job and dies mid folder-swap the
+    // moment the app quits. Creating the process via WMI (Win32_Process.Create)
+    // parents it to the WMI provider host, outside our job, so it survives.
+    const quoteForPowershell = (value) => `'${value.replace(/'/g, "''")}'`
 
-    installerProcess.unref()
+    const spawnerProcess = spawn(
+      'powershell.exe',
+      [
+        '-NoProfile',
+        '-NonInteractive',
+        '-WindowStyle',
+        'Hidden',
+        '-Command',
+        `$result = Invoke-CimMethod -ClassName Win32_Process -MethodName Create -Arguments @{ CommandLine = ${quoteForPowershell(installerCommandLine)} }; exit $result.ReturnValue`
+      ],
+      {
+        stdio: 'ignore',
+        windowsHide: true
+      }
+    )
 
-    installerProcess.on('error', async (error) => {
+    spawnerProcess.on('error', async (error) => {
       const output = await refreshInstallerOutput()
-      console.error('[app-update] installer error:', error)
+      console.error('[app-update] installer launch error:', error)
       settleFailure(getInstallErrorMessage(error, output))
     })
 
-    installerProcess.on('exit', async (code) => {
+    spawnerProcess.on('exit', async (code) => {
+      // PowerShell exits as soon as the installer is created; from here the
+      // log watcher owns success/failure. Only a non-zero code (WMI create
+      // failed) means the installer never started.
+      if (code === 0 || settled) return
+
       const output = await refreshInstallerOutput()
-
-      await fs.unlink(logPath).catch(() => {})
-
-      if (settled) return
-
-      if (code !== 0) {
-        settleFailure(
-          getInstallErrorMessage(
-            new Error(`Installer exited with code ${code}.`),
-            output
-          )
+      settleFailure(
+        getInstallErrorMessage(
+          new Error(`Failed to launch the update installer (code ${code}).`),
+          output
         )
-        return
-      }
-
-      if (
-        isWindowsInstallFailed(output) ||
-        !isWindowsInstallSuccessful(output)
-      ) {
-        settleFailure(getInstallErrorMessage(null, output))
-        return
-      }
-
-      settleSuccess(output)
+      )
     })
   })
 }