Installing Windows Server 2012 from ISO on ESXi 5.1
UPDATE: It seems that one host in this vSphere 5.1 cluster was running ESX 5.0 which may have been causing the issues I experienced. However, this approach may be helpful in similar environments where not all hosts are running 5.1.
Just a quick note on something I ran into. I was installing 2012 Server from ISO in order to make a VM template. I configured the VM (on ESXi 5.1) for Windows Server 2012, but after the first reboot I would get nothing but the spinning white dot-circle and high CPU on the VM.
I deleted the VM, and made a new one — this time changing the firmware from BIOS to EFI (options tab and select “Boot Options” on VM properties) and this fixed the problem and allowed me to complete the install. Not sure if there is a KB for this, but this seems to be an effective workaround.