diff --git a/native-messaging/README.md b/native-messaging/README.md
index 60fce8a0..8d69c6a5 100644
--- a/native-messaging/README.md
+++ b/native-messaging/README.md
@@ -16,7 +16,7 @@ To get this working, there's a little setup to do.
 
 ### Windows setup ###
 
-1. Check you have Python installed, and that your system's PATH environment variable includes the path to Python.  See [Using Python on Windows](https://docs.python.org/2/using/windows.html). You'll need to restart the web browser after making this change, or the browser won't pick up the new environment variable.
+1. Check you have Python installed, and that your system's PATH environment variable includes the path to Python.  See [Using Python on Windows](https://docs.python.org/3/using/windows.html). You'll need to restart the web browser after making this change, or the browser won't pick up the new environment variable.
 2. Edit the "path" property of "ping_pong.json" to point to the location of "ping_pong_win.bat" on your computer. Note that you'll need to escape the Windows directory separator, like this: `"path": "C:\\Users\\MDN\\native-messaging\\app\\ping_pong_win.bat"`.
 3. Edit "ping_pong_win.bat" to refer to the location of "ping_pong.py" on your computer.
 4. Add a registry key containing the path to "ping_pong.json" on your computer. See [App manifest location ](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_manifests#Manifest_location) to find details of the registry key to add.
diff --git a/native-messaging/check_config_win.py b/native-messaging/check_config_win.py
index 3bbfcaf2..d1d0ae3d 100755
--- a/native-messaging/check_config_win.py
+++ b/native-messaging/check_config_win.py
@@ -16,21 +16,15 @@
 # Assuming current user overrides local machine.
 key_roots = ['HKEY_CURRENT_USER', 'HKEY_LOCAL_MACHINE']
 
-found_key = False
-
-for root in key_roots:
-    key = winreg.OpenKey(getattr(winreg, root), key_path)
+for key_root in key_roots:
     try:
-        print('Checking:', root, key_path)
+        print('Checking:', key_root, key_path)
+        key = winreg.OpenKey(getattr(winreg, key_root), key_path)
         res = winreg.QueryValueEx(key, '')
+        break
     except FileNotFoundError:
-        print('...error finding key')
-        continue
-
-    found_key = True
-    break
-
-if not found_key:
+        print('... error finding key')
+else:
     raise ValueError('Could not find a registry entry, aborting.')
 
 json_path = res[0]