Problem with group permissions

I have installed Windows 2000 server and have a problem when assigning permissions to groups. Once I remove the everyone group the users loose all rights to the resources (folders or printers)regardless of what rights are given with the different group. For example I have a group of managers. Once I try to assign them rights t a folder and I remove the everyone group. The managers lose all rights to that folder. The only way to get them to have rights is to have everyone in the rights. Any ideas how to fix this?