The requirement for Windows Server 2012 Server Core installation option is the same with Server with a GUI installation. For more details requirements on Windows Server 2012 installation, you can refer to Windows Server 2012 installation with a GUI option.
Server Core Installation
To start the installation, power on the virtual machine created. The Windows installation will load the drivers and display the first interface screen.
Change the Installation Language and Time Zone if needed. Clicks [Next] to proceed.
On the next Windows Setup screen, clicks [Install Now] to start the Windows installation.
Windows Setup will prompt you to enter the 25-characters Product Key. This is the Windows Server 2012 License Product Key. You can either get this product key from Microsoft Volume License (MVL) or from the sticker on top of the server purchased (for OEM License). If you are installing an evaluation copy, this screen will not be displayed. For Windows Server 2012 evaluation copy, you will have a 180-days-trial period to the Windows activation.
The next screen is the Windows Server 2012 installation options. For this installation, we are choosing Windows Server 2012 Standard (Server Core). If you are installing an evaluation copy, you will have an additional Windows Server 2012 Datacenter edition on the list. Clicks [Next] to proceed.
You are then asked to check the License Terms box to accept the Microsoft Software License Terms. You cannot proceed with the installation without accepting License Terms. Check the box and click [Next] to proceed.
You will then give the options to upgrade or install a fresh copy of the Windows Server 2012. This screen is similar to the Windows Server 2008 R2 Setup. The upgrade option is to upgrade from the previous Windows version. Select the [Custom: Install Windows only (advanced)] for a fresh Windows installation.
Now, select the partition you want to install the Windows Server 2012. You may see multiple Disk Space from the list. It depends on how you configured allocation Disk. You can click on the Advanced option if you want further divide the Disk into multiple partitions.
After you have selected the partition and click [Next]. You are then completed the Windows installation selection. The Windows installation will begin to copy the Windows files and continue the installation. This process will take a while. You can take a break and come back after half an hour.
After the Windows installation is finished, it will restart on its own to complete the installation. The first screen display after Server restart is the Administrator account login password screen. In this screen, you are required to change the Windows Server default Administrator login password.
The Windows Server 2012 Server Core installation is completed. You are now can press Ctrl-Alt-Delete keys to log in to Windows Server 2012.
Upon login, you will see the Windows Command Prompt screen. You will see no user interface. All tasks execute will be through the command line.