Windows Small Business Server 2011 Essentials, Windows Home Server 2011, Windows Storage Server 2008 R2 Essentials, Windows Server 2012 Essentials.
Check the log, find the ESP partition offset info (in hexadecimal), and calculate the offset for ESP partition.
For example, if the value from log is 0x12d00000 (315621376 in decimal), start powershell in another machine, type the following command and press Enter:
The offset of ESP partition will be shown on the screen (300 in this case).
User should create a 300MB primary partition (It’s for system reserved or OEM partition purpose, and to make the EFI partition lay on the correct offset) at the leftmost area of the disk using diskpart, then create the EFI and MSR partition, and finally the
primary partition for your system drive. After that, map your system volume to the volume in this disk.
So the steps for diskpart should be:
Select disk 0
Create partition primary size=300
Create partition efi size=100
Create partition msr size=128
(Create your other primary partition after that)
For other steps, please refer to Client BMR user help file from wizard.