No domain option when logging on to DC

I recently upgrades a test domain from a workgroup to a domain the workgroup name was IRTech the doamin i created was IRTech.local.
after install and configuration , when i go to log on to the DC i am not presented with IRTech.local as a logon location. i have several Win9x clients configured and they are presented with the option to logon to the IRTech.local domain at logon , but when they attempt to logon they receive an error message “no domain server present to authenticate password” I canping the server from the client thru hostname or IP address and same from server. Im stumped by this ? any help would be GREATLY appreciated Thank you