to restrict an administrator to use a server as a workstation?
Answers:
You can just slow down an administrator from executing a database that you don't want them to execute. You cannot stop them completely from doing it, as they can simply bear rights surrounded by the ACL to execute it. It's similar to the adage that Power Users are Administrators that haven't elevated their privileges but... They most plausible own the power to do it, they simply entail to execute it properly.
I wonder why you're asking this type of put somebody through the mill, though. If you don't trust an administrator or user, you can contract out permissions to a standard user tale and you don't enjoy to generate them an administrator. This can be done through ADUC using the contract out way out. Right click on the OU and select farm out from the side-window to start the process.
Your other route is to not use a Windows Server for workstation purposes. Of course, if you enjoy a requirement for a server (such as more than 10 concurrent connections required), you enjoy to use a server and not a workstation class operating system. However, none of i.e. included in the examine, so I'm working on best guesses here.
WG