When you right click the Start button, you can select Open, Explore or Find options. To lock down this option, rename the key [HKEY_CLASSES_ROOT\Directory\shell] to [HKEY_CLASSES_ROOT\Directory\shell.lockdown] and rename the key [HKEY_CLASSES_ROOT\Folder\shell] to [HKEY_CLASSES_ROOT\Folder\shell.lockdown] . There is nothing magical about the lockdown extension. Don't delete these keys, just rename them. If you want to put the functionality back, all you need do is to rename the value back to "shell".
