Assign the drive letter S: to the EFI partition on Disk 1 and format it in FAT32: Then you have to prepare the EFI partition on the second disk in the mirror in order your computer can use this partition to boot Windows. How to Create GPT Mirror for EFI Partition? Now we’ll show you how to copy the EFI partition to the second disk and change the BCD bootloader configuration to enable booting Windows from both the first and second drives. It is quite hard for a beginner and takes some time (you may not have it if there is a crowd of angry users around). Since the OS boot files are located on the EFI partition, if the first disk fails, you won’t be able to boot from the second disk without the manual repairing of your EFI bootloader. In fact, you have protected your data (but not the Windows bootloader) from a failure of the second disk only.Ī software Windows RAID cannot be used to create a fully functional EFI partition mirror. However, the problem is that the bootloader configuration is stored only on the first drive, and if you lose it you won’t be able to boot Windows from the second drive without additional actions. If you do not select a disk manually, the system will try to boot from the first one in 30 seconds: When booting Windows, the Windows Boot Manager menu will appear where you can select what disk to boot from. Wait till it is over, it may take up to several hours depending on the size of the C: partition.

Open Disk Management and make sure that drive C: synchronization has been started (Resynching). The following message will appear: DiskPart succeeded in adding a mirror to the volume Select a partition on Disk 0 and create a mirror for it on Disk 1: Create a mirror for a system drive (drive letter C:).

Windows 10 boot drive