Administrator login issues

Well,
Im a student tech at reno highschool, Im currently working on a problem that not even our department chair can fix.
Its ongoing and tends to cause issues for those who dont know their way around it.
When going to log in through the novell log in client, the program randomly places "Administrator" Into the User name box.
You cant delete or backspace the administrator from the log in, the only way around it is to reboot. However, being at a highschool, most people tend to click ok and sign into the administrator account. Thus not being alloud to save and rarely print their documents.
We have yet to figure out what causes this "administrator" username.
Without knowing what is causing our problem it then becomes extremely difficult to solve it.
I need to know how to Disable all "workstation" and "administrator" accounts.
Let me know if you have any knowledge on this particular problem, It seems to be somewhat unique.
Please, dont hesitate to help. You would be saving alot of people, alot of time.