diff --git a/routlin/install.py b/routlin/install.py
index d191423..b0bc3c1 100644
--- a/routlin/install.py
+++ b/routlin/install.py
@@ -235,29 +235,32 @@ def _set_env_var(content, key, value):
     return new
 
 
-def setup_docker_compose():
+def _dash_already_configured():
+    if not COMPOSE_FILE.exists():
+        return False
+    return bool(re.search(r"^\s*- SECRET_KEY=\S", COMPOSE_FILE.read_text(), re.MULTILINE))
+
+def setup_docker_compose(reuse_config=False):
     header("Dashboard Configuration")
 
     if not COMPOSE_FILE.exists():
         die(f"docker-compose.yml not found at {COMPOSE_FILE}\n"
             f"  Ensure the routlin-dash directory is at {COMPOSE_FILE.parent}")
 
-    content = COMPOSE_FILE.read_text()
+    if reuse_config:
+        print("\n  Stopping existing container...")
+        subprocess.run(["docker", "compose", "down"], cwd=COMPOSE_FILE.parent, check=False)
+        print("\n  Starting dashboard container...")
+        result = subprocess.run(
+            ["docker", "compose", "up", "-d", "--build"],
+            cwd=COMPOSE_FILE.parent, check=False
+        )
+        if result.returncode != 0:
+            die("docker compose up failed. Check the output above.")
+        print("  Dashboard container started.")
+        return
 
-    existing_key = re.search(r"^\s*- SECRET_KEY=(.+)$", content, re.MULTILINE)
-    if existing_key and existing_key.group(1).strip():
-        print("  Dashboard is already configured.")
-        if not prompt_yn("Reconfigure? (generates a new SECRET_KEY, invalidates existing sessions)", default="n"):
-            print()
-            print("  Starting dashboard container...")
-            result = subprocess.run(
-                ["docker", "compose", "up", "-d", "--build"],
-                cwd=COMPOSE_FILE.parent, check=False
-            )
-            if result.returncode != 0:
-                die("docker compose up failed. Check the output above.")
-            print("  Dashboard container started.")
-            return
+    content = COMPOSE_FILE.read_text()
 
     print("  Generating SECRET_KEY...")
     secret_key = secrets.token_urlsafe(96)  # ~128 chars
@@ -455,7 +458,12 @@ def main():
     print("  be edited manually.")
     print()
 
-    want_dashboard = prompt_yn("Install the web dashboard?", default="y")
+    dash_installed = _dash_already_configured()
+    if dash_installed:
+        print("  Web dashboard is already installed.")
+        want_dashboard = prompt_yn("Rebuild?", default="n")
+    else:
+        want_dashboard = prompt_yn("Install the web dashboard?", default="y")
 
     if not want_dashboard:
         print()
@@ -466,6 +474,13 @@ def main():
         print("Done.")
         return
 
+    reuse_config = False
+    if dash_installed:
+        reuse_config = prompt_yn(
+            "Re-use existing configuration? (Keeps SECRET_KEY and SMTP credentials, preserving active sessions and email settings)",
+            default="y"
+        )
+
     # -- Docker ----------------------------------------------------
     header("Docker")
     if pm_ok:
@@ -476,7 +491,7 @@ def main():
         print("  Docker is already installed.")
 
     # -- docker-compose.yml ----------------------------------------
-    setup_docker_compose()
+    setup_docker_compose(reuse_config=reuse_config)
     create_dotfiles()
 
     # -- External access -------------------------------------------