Stop IE 5.5’s searching Other computers

I am setting up student pc’s w/ w2k and IE 5.5 sp2. When you select the search button in IE it will let the user search computers. All the have to do is type *.* and they will see all the NT/W2K machines out there. They still need to know passwords to get into the boxes but I would prefer not to tempt them. Does anyone know how to disable this?