diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 542418a..3969919 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,6 +19,7 @@ Thanks for your interest in contributing.
 
 - Install:
   - `cd frontend && npm ci`
+- **Windows — `EPERM` / `unlink` during `npm ci` (often `esbuild.exe`):** stop the dev server first (**Ctrl+C** where `npm start` / `ng serve` is running). Those processes lock files under `node_modules`. If it persists, end stray **Node.js** processes in Task Manager or add a short-lived antivirus exclusion for the repo folder.
 - Dev server — `frontend/proxy.conf.json` proxies **`/api`** → **`http://localhost:5002`** with **`changeOrigin: false`** (keep backend `Host` aligned with the SPA origin for tenant + BFF):
   - `npm start` or `ng serve` (default **http://localhost:4200**)
 - Lint:
diff --git a/frontend/README.md b/frontend/README.md
index b1709cf..1e7e78d 100644
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -22,9 +22,10 @@ Run `ng test` to execute the unit tests via [Karma](https://karma-runner.github.
 
 Tests live in `e2e/`. The **CI smoke** suite is `e2e/smoke.spec.ts` only.
 
-1. Install Chromium (once per machine): `npm run e2e:install-browsers`
-2. **Recommended (repo root):** start backend + dev server via `bash scripts/e2e-smoke-ci.sh` (Unix) or `powershell -File scripts/e2e-smoke-ci.ps1` (Windows), which set `PW_NO_WEBSERVER=1` and run `npm run e2e:smoke` in this directory.
-3. **Manual:** run the backend on **:5002** and `npm start` here on **:4200**, then in this directory:  
+1. Install dependencies: `npm ci` (if **`EPERM`** on Windows, stop **`npm start`** / **`ng serve`** first — see [`CONTRIBUTING.md`](../../CONTRIBUTING.md)).
+2. Install Chromium (once per machine): `npm run e2e:install-browsers`
+3. **Recommended (repo root):** start backend + dev server via `bash scripts/e2e-smoke-ci.sh` (Unix) or `powershell -File scripts/e2e-smoke-ci.ps1` (Windows), which set `PW_NO_WEBSERVER=1` and run `npm run e2e:smoke` in this directory.
+4. **Manual:** run the backend on **:5002** and `npm start` here on **:4200**, then in this directory:  
    - **Unix:** `PW_NO_WEBSERVER=1 npm run e2e:smoke`  
    - **Windows (cmd):** `set PW_NO_WEBSERVER=1&& npm run e2e:smoke`