IBM Laptop logon

One of my IBM Laptop 390x with IBM PC card, running Windows 98, when it first boot up, it always boots to windows logon, if I want to connect to my NT server, I need to first logoff from local windows and re-logon the second time, only then is network available. My other desktop computer have no such problem with network. My users usually always geet the network logon as soon as the computers boot. Any ideas please?