The computer management console for Server 2008 has changed slightly between now and Windows Server 2003. I was trying to ensure a particular user was setup as a local administrator on a Windows 2008 Small Business Server today, and couldn’t find the option to do this via the GUI. Anyway, for those wondering how this is done using the command prompt, here is the solution.
First you need to run command prompt as an Administrator. Open Computer, go to your C: drive, and navigate to your Windows\System32 directory. Find “cmd.exe” right click on it, and select the run as Administrator option. Once at the command prompt, type the following :
net localgroup Administrators /add (domain)\(username)
(Obviously replace (domain)\(username) with your domainname\username that you want to be the local admin) – That is without the brackets.
You should get a message saying the command completed successfully. If you get an access denied error, you more than likely have not run cmd.exe as an administrator.