Asking for a password for shared folders

Is there anyway that I can setup things in security such a way that when ever a client machine ( Win 95 and NT) accesses any shared
folders from the Server it asks for a admin
password to have access to that and secondly also when ever somebody tries to access $C or $D drive on the Server it should ask for admin password and so that the clients machine are not able to access it without admin password.

Thanks