You can disable the automatic administrative share creation via Group Policy, but this is a much simpler way:
In order to disable these shares permanently, a registry edit will be necessary.
create AutoShareServer AutoShareWks both REG_DWORD Value: 0
The default-hidden shares are:
C$ D$ E$ - Root of each partition. For a Windows NT workstation/W2K/2003/XP Professional computer only members of the Administrators or Backup Operators group can connect to these shared folders. For a Windows NT Server/W2K Server computer, members of the Server Operators group can also connect to these shared folders.
ADMIN$ - %SYSTEMROOT% This share is used by the system during any remote administration of a computer. The path of this resource is always the path to the W2K/NT system root (the directory in which W2K/NT is installed usually C:\Winnt and in XP it's C:\Windows).
FAX$ - On W2K Server, this used by fax clients in the process of sending a fax. The shared folder temporarily caches files and accesses cover pages stored on the server.
IPC$ - Temporary connections between servers using named pipes essential for communication between programs. It is used during remote administration of a computer and when viewing a computer's shared resources. This share can be very dangerous and can be used to extract large amounts of information about your network, even by an anonymous account.
NetLogon - This share is used by the Net Logon service of a W2K, 2003 and NT Server computer while processing domain logon requests, and by Pre-W2K computers when running logon scripts.
PRINT$ - %SYSTEMROOT%\SYSTEM32\SPOOL\DRIVERS Used during remote administration of printers.