diff --git a/build/installer.nsh b/build/installer.nsh
index 1ac6f25..98ca94e 100644
--- a/build/installer.nsh
+++ b/build/installer.nsh
@@ -4,3 +4,42 @@
   IfFileExists "$INSTDIR\resources\app.asar.unpacked\vendor\redist\vc_redist.x64.exe" 0 +2
     ExecWait '"$INSTDIR\resources\app.asar.unpacked\vendor\redist\vc_redist.x64.exe" /install /quiet /norestart' $0
 !macroend
+
+; ---------------------------------------------------------------------------------------------------
+; Replaces electron-builder's "is the app running?" check (customCheckAppRunning). Runs at the start of
+; installing, BEFORE the old version is removed and before any file is copied.
+;
+; The stock check only looks for "Bible App.exe". But the app also starts programs from its own folder
+; - the local AI server (llama-server.exe), speech (whisper), the upscaler - and if the app is closed
+; hard, those are left running. They hold their files open, so copying the new version fails and the
+; installer says "Bible App cannot be closed. Please close it manually and click Retry" even though
+; the app is plainly closed, and Retry can never succeed. So:
+;   1. ask the app to close (it then stops the AI server itself), and give it a moment;
+;   2. force-close anything named Bible App.exe that is still there;
+;   3. force-close the app's own helper programs by name (plain taskkill, nothing to go wrong);
+;   4. as a backstop, force-close EVERY program running from this install folder, whatever its name.
+; Step 4 matches by folder, via WMI (works from this 32-bit installer on 64-bit Windows, where a
+; 32-bit process cannot read a 64-bit process's path). The folder travels in an environment variable
+; so a quote or space in it can never break the command, and it refuses to act on a bare drive.
+; No question is asked first: installing this version replaces the app, which is what was asked for.
+; ---------------------------------------------------------------------------------------------------
+!macro customCheckAppRunning
+  DetailPrint `Closing "${PRODUCT_NAME}"...`
+  nsExec::Exec `"$SYSDIR\cmd.exe" /c taskkill /im "${APP_EXECUTABLE_FILENAME}" /fi "USERNAME eq %USERNAME%"`
+  Pop $0
+  Sleep 2500
+  nsExec::Exec `"$SYSDIR\cmd.exe" /c taskkill /f /t /im "${APP_EXECUTABLE_FILENAME}" /fi "USERNAME eq %USERNAME%"`
+  Pop $0
+  nsExec::Exec `"$SYSDIR\cmd.exe" /c taskkill /f /t /im llama-server.exe /im whisper-cli.exe /im realesrgan-ncnn-vulkan.exe /fi "USERNAME eq %USERNAME%"`
+  Pop $0
+  System::Call 'Kernel32::SetEnvironmentVariable(t "BIBLEAPP_INSTDIR", t "$INSTDIR")'
+  StrCpy $1 "$SYSDIR\WindowsPowerShell\v1.0\powershell.exe"
+  ${If} ${FileExists} "$WINDIR\Sysnative\WindowsPowerShell\v1.0\powershell.exe"
+    StrCpy $1 "$WINDIR\Sysnative\WindowsPowerShell\v1.0\powershell.exe"
+  ${EndIf}
+  StrCpy $2 `"$1" -NoProfile -NonInteractive -ExecutionPolicy Bypass -Command "$$r = $$env:BIBLEAPP_INSTDIR.TrimEnd('\'); if ($$r.Split('\').Count -lt 2) { exit }; $$d = $$r + '\'; Get-CimInstance Win32_Process | Where-Object { $$_.ExecutablePath -and $$_.ExecutablePath.StartsWith($$d, [StringComparison]::OrdinalIgnoreCase) } | ForEach-Object { Stop-Process -Id $$_.ProcessId -Force -ErrorAction SilentlyContinue }"`
+  DetailPrint `Closing anything else still running from "${PRODUCT_NAME}"'s folder...`
+  nsExec::Exec $2
+  Pop $0
+  Sleep 1000
+!macroend
diff --git a/main.cjs b/main.cjs
index 2b05063..14fb970 100644
--- a/main.cjs
+++ b/main.cjs
@@ -355,6 +355,9 @@ async function createWindow () {
         quit: () => { try { app.quit(); } catch (_) {} },
         runInstaller: (installerPath) => {
           // Launch the installer detached, then quit so it can replace the running app.
+          // Stop the local AI server FIRST: it runs from the install folder, and one left running holds
+          // its files open, so the installer cannot copy the new version over them ("cannot be closed").
+          try { stopLlamaServer(); } catch (_) {}
           try {
             const { spawn } = require('child_process');
             const child = spawn(installerPath, [], { detached: true, stdio: 'ignore', windowsHide: false });