cant log onto NT

i had a nt workstation NT4 which a user could not log onto but he could log onto other computers. i later found out that no one could log onto this PC. we are runni9ng NT4 in a domain enviroment with a PDC and 1 BDC. whren trying to log onto the network form this workstation the eror would be: the operating system could not log you on please contact your system administrator.when i tried to log on as administartor i logged in but got the error: cant load profile. we use roaming profiles and i checked and tcp/ip was all ok ip adress and subnet mask was all ok as well.