Presumably by "disable" you mean deny logon?

You can do this simply by creating an ini file. Create an entry for each user you want to deny access and set the entry value ro "1" to deny acess, and "0" to allow it.

During login, check the ini file for an entry keyed by the user name. If present and not zero log the user off.

The problem with this solution is that it won't affect anyone who is already logged on, and it won't stop savvy users from manually making or reattaching remembered network connections. The best solution to that is to put all your "disabled" users into a disabled group, and set the permissions on your resources (shares, printers, whatever) such that they have no access while in the disabled group.

{edit}
You could also use membership of the disabled group to trigger the logoff rather than use the ini file.
{/edit}

[ 19. December 2002, 12:52: Message edited by: Richard Howarth ]