A dedicated admin server will be a physical server as opposed to a workstation or desktop machine. It will be running a Microsoft Server Operating System (2003, 2008 etc)
If you have a Workstation File Server (WSFS) this is not a dedicated admin server.
A dedicated server is usually in a secure location that is not in use as a workstation for day to day tasks. It is the machine on the admin network that is regularly backed up usually with the Scomis remote backup service or with a tape drive.
The following will assist in discovering if you are using a dedicated admin server:
Check if the SIMS Server (the machine where SIMS is installed and backed up) is running a server operating system. The following web page explains how to find out: http://windows.microsoft.com/en-US/windows7/help/which-version-of-the-windows-operating-system-am-i-running
Check the local SIMS.ini file. Click start > then Run > then type in “SIMS.ini”. When the text file comes up, check the entry for SIMSDirectory – if it contains “F:\Public\SIMS” or D:\Admin\Public\SIMS it is potentially a dedicated server.