The Domain Controller (Server)
Each individual workstation would control its own access. Whereas in a domain environment the server would control access to each individual workstation.
In terms of the internet: A domain is a specific 32-bit URL address on the internet usually shown as 4 numbers separated by dots (ex: 70.100.145.175) or as alphanumeric name (ex: www.wikianswers.com). A workstation is one computer within a domain.
Remove the workstation from the domain then rejoin the workstation to the domain. ...if you want to run the risk of losing some security credentials. When you leave and rejoin the domain you are no longer in the same machine account. The simple fix is to log in as a local admin and from the command prompt type: netdom.exe resetpwd /s:<x.x.x.x> /ud:<AccountName> /:pd* Where <x.x.x.x> is address of a domain controller and <AccountName> is a domain account. You will be prompted for the password for the account you used and 2 seconds later the job is done. You do not need to reboot just log off your local admin and carry on. Your machine password will have been reset and trust restored.
If your question is novella-length or more, we can't answer it here. I suspect you need to hire a consultant who knows something about Active Directory domain administration.
members option
Restricted Groups
Contact her administrator
"the trust relationship between this workstation and the primary domain failed," ...
Contact her administrator
This depends on the Operating System in use. In Microsoft Windows, it can be done by changing the setting in the system properties dialogue box of My Computer.
There might be different reasons but one of them is that the clocks between a workstation is a DC are not syncronised. I believe Windows allow not more than 1 minute difference