System Requirements for Windows Server 2012 Essentials

Component Minimum Recommended
CPU socket 1.4 GHz (64-bit processor) or faster for single core 1.3 GHz (64-bit processor) or faster for multi-core 3.1 GHz (64-bit processor) or faster multi-core
Memory (RAM) 2 GB 8 GB
Hard disks and available storage space 160 GB hard disk with a 60 GB system partition