How can I stop a user logging on more than once?

A. There is no way in NT to stop a user logging on more than once, however it is possible to restrict a workstation so that only a certain user can login, and with this method each user would be tied to one workstation and thus could only logon once.

This solution is far from ideal, and it may be plausible to write a login script that checked if a user was currently logged on and if so, logoff straight away (using the logout command line tool).

Another method is to set the users logon share to one connection only and as part of the logon script open a file from the logon share which mean if they were already logged on a second logon would be unable to connect to the share and the logon would fail.

The Windows 2000 Resource kit introduces the CConnect.exe utility which:

Con-Current Connection Limiter is not installed by the Windows 2000 Resource Kit setup program. The files required for this tool are located on the AppsCconnect folder of the Resource Kit companion CD.

Before using CConnect Client or CConnect Administrator, you must first install them using the installation programs (Setup.exe) located in the AppsCconnectClient and AppsCconnectAdmin folders.