diff --git a/.github/workflows/desktop-installers.yml b/.github/workflows/desktop-installers.yml
index b60a2ae..9a80076 100644
--- a/.github/workflows/desktop-installers.yml
+++ b/.github/workflows/desktop-installers.yml
@@ -72,7 +72,7 @@ jobs:
             {
               "os_key": "windows",
               "platform": "windows-latest",
-              "args": "--target x86_64-pc-windows-msvc",
+              "args": "--target x86_64-pc-windows-msvc --bundles nsis",
               "rust_target": "x86_64-pc-windows-msvc",
               "artifact": "desktop-windows-x86_64"
             }
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index a6f729d..ceef3ec 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -94,7 +94,7 @@ jobs:
             rust_target: aarch64-apple-darwin
             artifact: desktop-macos-aarch64
           - platform: windows-latest
-            args: --target x86_64-pc-windows-msvc
+            args: --target x86_64-pc-windows-msvc --bundles nsis
             rust_target: x86_64-pc-windows-msvc
             artifact: desktop-windows-x86_64
     runs-on: ${{ matrix.platform }}
@@ -270,7 +270,7 @@ jobs:
             |----------|----------|
             | Linux x86_64 | `.deb` / `.AppImage` |
             | macOS Apple Silicon | `.dmg` |
-            | Windows x86_64 | `.msi` / NSIS `.exe` |
+            | Windows x86_64 | NSIS `.exe` |
 
             ### Notes
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7830b3..4e322f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ Versions follow [SemVer](https://semver.org/) (`0.1.0-alpha.x` while the public
 ### Fixed
 
 - Committed Tauri `gen/schemas/capabilities.json` aligned with source capabilities (no `shell:allow-open`)
+- Windows packaging uses NSIS only — WiX `.msi` rejects semver pre-releases like `0.1.0-alpha.1`
 
 ## [0.1.0-alpha.1] - TBD
 
diff --git a/apps/desktop/README.md b/apps/desktop/README.md
index 4251cef..e551294 100644
--- a/apps/desktop/README.md
+++ b/apps/desktop/README.md
@@ -56,7 +56,7 @@ CI (`ci.yml`) runs unit tests + typecheck only. Desktop installers are built on
 |---------------|------------------|
 | `desktop-linux-x86_64` | `.deb` / `.AppImage` under `bundle/` |
 | `desktop-macos-aarch64` | `.dmg` / `.app` under `bundle/` |
-| `desktop-windows-x86_64` | `.msi` / NSIS `.exe` under `bundle/` |
+| `desktop-windows-x86_64` | NSIS `.exe` under `bundle/` |
 
 ```bash
 gh workflow run "Desktop Installers" -f platforms=windows-and-linux
@@ -72,8 +72,9 @@ Use the **Release** workflow (Actions → **Release** → **Run workflow**) to b
 - Input `prerelease`: leave on for alphas
 - Or push a tag `v*` (hyphenated versions such as `v0.1.0-alpha.1` are treated as pre-releases)
 
-Assets attached to the release are the platform installers (`.deb` / `.AppImage`, `.dmg`, `.msi` / `.exe`).
+Assets attached to the release are the platform installers (`.deb` / `.AppImage`, `.dmg`, NSIS `.exe`).
 
+Windows uses **NSIS only** (not WiX `.msi`). MSI requires a numeric-only pre-release (`0.1.0-1`); versions like `0.1.0-alpha.1` fail the WiX bundler. NSIS accepts full semver.
 ## Icons
 
 Source mark: `apps/desktop/app-icon.png` (1024²). Regenerate platform icons with:
diff --git a/apps/desktop/src-tauri/tauri.conf.json b/apps/desktop/src-tauri/tauri.conf.json
index bebf9e2..194362c 100644
--- a/apps/desktop/src-tauri/tauri.conf.json
+++ b/apps/desktop/src-tauri/tauri.conf.json
@@ -17,7 +17,7 @@
   },
   "bundle": {
     "active": true,
-    "targets": "all",
+    "targets": ["app", "dmg", "deb", "appimage", "nsis"],
     "icon": [
       "icons/32x32.png",
       "icons/128x128.png",
diff --git a/docs/architecture/LOCAL_STACK.md b/docs/architecture/LOCAL_STACK.md
index 7468bff..6b3d5da 100644
--- a/docs/architecture/LOCAL_STACK.md
+++ b/docs/architecture/LOCAL_STACK.md
@@ -10,7 +10,7 @@ Primary target: installable app on **Linux, Windows, macOS**. No Docker/Postgres
 
 | Layer | Choice | Notes |
 |-------|--------|-------|
-| Shell | **Tauri 2** | dmg / msi|NSIS / AppImage|deb (manual **Desktop Installers** `workflow_dispatch`) |
+| Shell | **Tauri 2** | dmg / NSIS / AppImage|deb (manual **Desktop Installers** `workflow_dispatch`; no WiX MSI while versions use `alpha` pre-release) |
 | UI | **React + TypeScript + Vite** | |
 | Backend (shipped) | **Node Hono sidecar** on `127.0.0.1` + session token; desktop adds **per-launch capability token** | Prefer migrating privileged ops to Tauri IPC over time |
 | Backend (target) | Tauri IPC commands for DB/FS/HTTP without a long-lived TCP sidecar | Aspirational |