Log on domain with win98

Hi, since a few weeks, i’m unable to log on my NT domain using a machine with Windows 98. This appened with 2 computers with Win98. I type the login and password and I am accepted but the system jam just after. When I skip the login by pressing “ESC” I can open my session with no access to the network. When I authenticate to the domain, i’m unable to open the session, I need to reboot. If somebody could help me with this, I would greatly appreciate.
Thank You.