Invalid Access Code

Enviroment: Win2000Server, Win98SE clients; Okipage 24 and 14e connected to server, additional drivers installed; no matter what you print from client you immediately receive an “Invalid Acces Code” error message. If I load HP Laserjet 5 drivers on server, everything prints. I have checked all permissions and even logged on to clients as administrator. I checked the event viewer and saw that the “real” meaning of the message is “unrecognized driver”; Any help?