Deletes a subkey and all its descendants
_WinAPI_RegDeleteTree ( $hKey [, $sSubKey = ''] )
|$hKey||Handle to an open registry key, or any of the following predefined keys.
|$sSubKey||[optional] The name of the key to delete.|
|Failure:||0 and sets the @error flag to non-zero, @extended flag may contain the system error code.|
Search SHDeleteKey in MSDN Library.