For EFI computers that boot from a GPT disk, the boot disk must contain at least the following partitions:

• EFI System Partition On EFI computers, the EFI System Partition (ESP) is about 100 megabytes (MB) and contains the Windows Boot Manager files.
• Microsoft Reserved Partition The Microsoft Reserved Partition (MSR) reserves space on each disk drive for subsequent use by operating system software. On drives smaller than 16 gigabytes (GB), the MSR is 32 MB. On drives 16 GB or larger, the MSR is 128 MB.
• Data partition This partition stores Windows 7 system files and user files.
• A data container partition corresponding to the MBR partition 0x42.
• A partition to contain the dynamic configuration database