Windows 2000 slams the door shut on hackers trying to steal your username and password by sniffing the network. Microsoft has leveraged the power of Kerberos and IPsec to let the good people in and the bad people out. Unfortunately, the default security closed the door, but left the window open.
Internet Information Server (IIS) supports the Internet Printing Protocol. A widely publicized hack is now making the rounds where you can overflow the buffer and force execution of any desired application that will then run under the system security context. That means the 14-year-old script-monkey hacker now has more authority on your system than even the enterprise admin.
To prevent this and other hacks, you need to apply the new security hotfix that is now available on the Microsoft site. But there is still another layer to the security onion.
You need to go to the IIS Inetpub, and disable permission inheritance, making sure you copy the currently assigned permissions. Make sure you check your Inetpub directory to ensure the anonymous Web account has any necessary permissions required to view your Web content. On the root of all of your logical drives, add the IUSER_%Computername% account with the Deny permission. (You are using NTFS, right?) If a hacker penetrates the sieve we all know as IIS, they will be explicitly denied any form of permissions and will only be able to scratch their heads in frustration.