This is exactly what I have been looking for. I run a personal file server for my department, but didn't want anyone, i.e. guest, to be able to access my computer. Untill today, I had to settle to allow guest access on my computer. Before I had used SharePoints so he public folders were not being shown but that still left the ability to log in as guest across the network. This nice little utility keeps people from even attempting to log in as guest by greying out the guest option. Nice work.