1) Open from cmd the regedit.exe comamnd
2) open the path:
HKEY_CLASSES_ROOT\Directory\Background\shellex\ContextMenuHandlers
3) save (with export option) the branch in your computer.
4) delete entries one at a time, and try right-clicking each time.
5) when you find the item that locks the menus, reload the file saved in
your computer and remove only that item
If you want to use a program yo can use ShellExView
