Open your registry and find the key [HKEY_CLASSES_ROOT\Directory\shell] then rename it from 'shell' to 'shell.old'.
Do the same with the key [HKEY_CLASSES_ROOT\Folder\shell] and rename it to [...\shell.old].
Once complete the two original keys should now be called [HKEY_CLASSES_ROOT\Directory\shell.old] and [HKEY_CLASSES_ROOT\Folder\shell.old] respectively.
Now when you right click on the start button, you should no longer be given the option to Open, Explore or Find.
