# Buggy code
def list_keys(hive, key=None, use_32bit_registry=False):
    """
    Enumerates the subkeys in a registry key or hive.

    :param str hive: The name of the hive. Can be one of the following

        - HKEY_LOCAL_MACHINE or HKLM
        - HKEY_CURRENT_USER or HKCU
        - HKEY_USER or HKU
        - HKEY_CLASSES_ROOT or HKCR
        - HKEY_CURRENT_CONFIG or HKCC

    :param str key: The key (looks like a path) to the value name. If a key is
        not passed, the keys under the hive will be returned.

    :param bool use_32bit_registry: Accesses the 32bit portion of the registry
        on 64 bit installations. On 32bit machines this is ignored.

    :return: A list of keys/subkeys under the hive or key.
    :rtype: list

    CLI Example:

    .. code-block:: bash

        salt '*' reg.list_keys HKLM 'SOFTWARE'
    """

    local_hive = _to_unicode(hive)
    local_key = _to_unicode(key)

    registry = Registry()
    hkey = registry.hkeys[local_hive]
    access_mask = registry.registry_32[use_32bit_registry]

    subkeys = []
    try:
        handle = win32api.RegOpenKeyEx(hkey, local_key, 0, access_mask)

        for i in range(win32api.RegQueryInfoKey(handle)[0]):
            subkey = win32api.RegEnumKey(handle, i)
            if PY2:
                subkeys.append(_to_mbcs(subkey))
            else:
                subkeys.append(subkey)

        handle.Close()

    except Exception:  # pylint: disable=E0602
        log.debug(r"Cannot find key: %s\%s", hive, key, exc_info=True)
        return False, r"Cannot find key: {0}\{1}".format(hive, key)

    return subkeys


# Traceback (TypeError)
local:
---------
ID: test_reg
Function: reg.present
Name: HKEY_LOCAL_MACHINE\SOFTWARE\salttest\salty\salted
Result: False
Comment: An exception occurred in this state: Traceback (most recent call last):
File "c:\salt\bin\lib\site-packages\salt\state.py", line 1878, in call
**cdata['kwargs'])
File "c:\salt\bin\lib\site-packages\salt\loader.py", line 1823, in wrapper
return f(*args, **kwargs)
File "c:\salt\bin\lib\site-packages\salt\states\reg.py", line 196, in present
vdata_decoded = salt.utils.stringutils.to_unicode(vdata, 'utf-8')
File "c:\salt\bin\lib\site-packages\salt\utils\stringutils.py", line 99, in to_unicode
raise TypeError('expected str, bytes, or bytearray')
TypeError: expected str, bytes, or bytearray

# Fixed code
def list_keys(hive, key=None, use_32bit_registry=False):
    """
    Enumerates the subkeys in a registry key or hive.

    :param str hive: The name of the hive. Can be one of the following

        - HKEY_LOCAL_MACHINE or HKLM
        - HKEY_CURRENT_USER or HKCU
        - HKEY_USER or HKU
        - HKEY_CLASSES_ROOT or HKCR
        - HKEY_CURRENT_CONFIG or HKCC

    :param str key: The key (looks like a path) to the value name. If a key is
        not passed, the keys under the hive will be returned.

    :param bool use_32bit_registry: Accesses the 32bit portion of the registry
        on 64 bit installations. On 32bit machines this is ignored.

    :return: A list of keys/subkeys under the hive or key.
    :rtype: list

    CLI Example:

    .. code-block:: bash

        salt '*' reg.list_keys HKLM 'SOFTWARE'
    """

    local_hive = _to_unicode(hive)
    local_key = _to_unicode(key)

    registry = Registry()
    try:
        hkey = registry.hkeys[local_hive]
    except KeyError:
        raise CommandExecutionError("Invalid Hive: {0}".format(local_hive))
    access_mask = registry.registry_32[use_32bit_registry]

    subkeys = []
    try:
        handle = win32api.RegOpenKeyEx(hkey, local_key, 0, access_mask)

        for i in range(win32api.RegQueryInfoKey(handle)[0]):
            subkey = win32api.RegEnumKey(handle, i)
            if PY2:
                subkeys.append(_to_mbcs(subkey))
            else:
                subkeys.append(subkey)

        handle.Close()

    except Exception:  # pylint: disable=E0602
        log.debug(r"Cannot find key: %s\%s", hive, key, exc_info=True)
        return False, r"Cannot find key: {0}\{1}".format(hive, key)

    return subkeys