This issue is likely caused by the following:

  1. The machine account password has expired. The computer will then contact the server to re-sync the password. By default this occurs every 30 days. If the computer cannot contact back to the domain, it will cause a trust relationship error. 
  2. Another possibility is that an old computer with the same name is turned on. It then contacts the domain and sync's its machine account with the server. This will break the trust relationship with the new computer. 

The solution in either case is to rejoin your computer with the domain. This will force your computer to resync the password. You will need to call the Campus Support Center (Phone: (479) 968-0646; Email: [email protected]) or submit a support ticket at http://support.atu.edu.