diff --git a/docs/guides/SETUP_GUIDE.md b/docs/guides/SETUP_GUIDE.md
index fdd622c1ec..68bf2e8e90 100644
--- a/docs/guides/SETUP_GUIDE.md
+++ b/docs/guides/SETUP_GUIDE.md
@@ -56,6 +56,8 @@ npm install
 PORT=20128 DASHBOARD_PORT=20129 NEXT_PUBLIC_BASE_URL=http://localhost:20129 npm run dev
 ```
 
+> **Windows note:** By default, OmniRoute uses `%APPDATA%\omniroute` when the legacy `%USERPROFILE%\.omniroute` directory is not present. Set `DATA_DIR` to choose a different data-directory location.
+
 > **Note:** `npm install` auto-generates `.env` from `.env.example` on first run. Subsequent installs will not overwrite an existing `.env`, so customizations are preserved. To re-seed, delete `.env` before re-running.
 
 ### Docker