Reference Guide

20 Installing Microsoft Windows Server 2008 R2
NOTE: It is recommended that you use the GPT partition scheme as it is more
flexible, supports larger hard drive sizes, and has a number of features and
recovery mechanisms that are not available in the MBR partition scheme.
For more information on partitions and volumes, see partitions and volumes
on technet.microsoft.com. For more information on GPT, see the Windows
and GPT frequently asked questions on microsoft.com.
NOTE: GPT boot (UEFI boot) is supported only on 11G or newer platforms.