this line will throw when you create required key in HKEY_LOCAL_MACHINE instead of HKEY_CURRENT_USER ( which is allowed ) , so this script should not behave like this :

also , as the script is in Python anyway , the whole thing can be simplified using for-else :

for root in key_roots:
    try:
        key = winreg.OpenKey(getattr(winreg, root), key_path)
        print('Checking:', root, key_path)
        res = winreg.QueryValueEx(key, '')
    except FileNotFoundError:
        continue
    break
else:
    raise ValueError('Could not find a registry entry, aborting.')

let me know if you want me rather create a small PR with this fix