Microsoft Windows Home Server 2011 X64 Iso Link -

Note: WHS 2011 does support UEFI boot or installation on drives larger than 2TB for the system partition.

Unlike newer server OSes, WHS 2011 does not support UEFI boot natively out of the box for installation media. You will likely need to enable Legacy/CSM mode in your BIOS. Microsoft Windows Home Server 2011 X64 ISO