You will have a message that says, ""the trust relationships between the workstation and the primary domain failed" at Windows login. You will need to leave and re-join the domain in order to gain access.
To Resolve: Edit
1. Unplug the ethernet cable from the back of the workstation.
2. Login as a local user instead of the domain profile your used to. Make sure you are selecting (This computer). Use the local "administrator" account if you can't remember yours, you will need "administrator" privileges.
a. To force a local login with a computer on a domain, use ".\username" as the username if you don't know the computer name. If you do know the computer name, obviously, do the standard "computername\username" to login as a local user instead of a domain user.
3. Once in Windows, plug the ethernet cable back in.
4. Use the keyboard shortcut Win+Pause/break to bring up the "System Properties" box. Under the "Computer Name" tab, take note of the domain name and change the computer from a Domain to a Workgroup (choose any name you want for the workgroup). Use whatever credentials you want to change to a workgroup, it doesn't matter.
5. Restart the workstation and log back in the "Administrator" account or whichever account you were on with Administrator rights.
6. Go back to they "System Properties" (Run - sysdm.cpl) and change the computer from a Workgroup back to a Domain. Here, make sure you enter the local administrator account's username/ password to the server.
7. Restart the machine again. Now login to the domain. If it still doesn't work, you need to login to the DC (Domain Controller) and check your user's account settings under Start - Administrative Tools - Active Directory Users and Computers.