logon

I have a win98 machine belonging to a domain. With that machine I can log on to the NT server in the network too. But the problem is when I start this machine, it doesnot boot up so as to have access to the server. I have to log off and login again and only then it asks for the user/passwd. I can then access the server. I want to have that machine ask for the login user/passwd the first time it boots so that the user using that machine can have access to the server. Any suggestion?