What is EFI partition and why clone it
An EFI (Extensible Firmware Interface) system partition, or ESP for short, is a partition on a HDD or SSD that is used by computers with a Unified Extensible Firmware Interface (UEFI). Both GPT and MBR partitioned disks can contain an EFI system partition, as UEFI firmware is required to support both partitioning schemes.
Windows boot files are stored in EFI partition. When the computer is booted, the UEFI firmware loads the files stored on the ESP and begins installing the operating system and various utilities. If you delete the EFI partition by mistake or it is corrupted, Windows will fail to boot. That is why it is hidden and you cannot delete it with Windows running. If you open Disk Management, you can see the EFI partition at the beginning of the hard drive.
✎As it is so crucial for booting Windows, you should have a backup of the EFI partition. One easy solution is to make a clone of the EFI system partition. Besides, cloning is the easiest way if you want to transfer the system including the hidden ESP to another drive.
Preparations before cloning EFI system partition
👉Prepare the target device for ESP cloning
- You usually do not clone the EFI partition alone, but the entire operating system or disk containing the ESP, so your target disk should have enough space to accommodate the size of the existing data.
- Then, install the target drive to your computer and make sure it can be detected. If your computer does not have an extra slot, you may need to connect it via an adapter or enclosure.
- The cloning will overwrite everything on the target drive, so if there's any important data, please make a backup first.
👉Clean your source hard drive
- It's recommended to deleted unwantted data on the source drive before cloning.
- Uninstall those apps that you don't really need. This can also save you much storage space.
👉Pick an effective cloning software
Whether it's Windows 11, 10, 8.1/8, 7 or Vista/XP, while you can find some backup features, the cloning functionality is always missing. To clone EFI partition, you still need a bootable cloning software that fully supports UEFI.
Based on these conditions, I would recommend AOMEI Backupper Professional, which works well on all Windows OS, and enables you to clone operating system, entire disk, or specified partition.
It supports both MBR/Legacy BIOS and GPT/UEFI disks, and the SSD Alignment features helps to accelerate the target SSD. Besides, you can use the Edit Partitions feature to clone and resize hard drive, thus allocate unused space and fully utilize disk capacity.
Download the free demo to experience the cloning features:
*The Professional edition works on all Windows Clinet OS. If you are running Windows Server, try Server edition.
👉Make the partition style compatible with the boot mode.
The partition style (MBR/GPT) of a disk should be compatible with the boot mode of the computer (MBR for Legacy BIOS and GPT for UEFI). Although AOMEI Backupper supports cloning MBR to GPT/GPT to MBR without conversion, but depending on the circumstances, you may need to convert the partition style of the target drive. To check the current partition style of a disk:
- Press Win + R to open the Run window
- Type "diskmgmt.msc" and hit OK to open disk management
- Right-click the disk you want to check and click "Properties"
- Then, select "Volume" tab to check the "Partition style"
Steps to clone EFI boot partition
AOMEI Backupper contains 3 options: System Clone, Disk Clone and Partition Clone. Although you can use the 3rd option to clone a single partition, considering the boot issue, it's recommended to use the System Clone or Disk Clone feature.
How to clone a disk with EFI partition step by step:
1. Download and run this free cloning software. In the Home screen, click “Clone” and select “Partition Clone”. If you only want to make a bootable clone of the operating system, choose “System Clone” instead.
2. Choose the disk including EFI system partition as the source, and then select a target disk to receive the cloning.
3. Click “Start Clone” to start the EFI partition clone.
Before that, you can also make use of the following features:
✍Sector By Sector Clone: clone all sectors whether it is used or not, even logically bad sectors, and it will cost longer time.
✍SSD Alignment: if you are cloning EFI partition to SSD, make sure you have checked this option to speed up the SSD reading & writing performance, and prolong its lifespan.
✍Edit Partitions: Manage disk space and make the full use of the capacity of the target disk. You have 4 options:
- Copy without resizing partitions: It will not resize the partition size.
- Add unused space to all partitions: Reallocate the unallocated space to each partition of the target disk.
- Manually adjust partition size: Extend unallocated space to any partition on the target disk you want.
- Convert the destination disk...: Convert the partition style of the target disk to make it the same as the source.
AOMEI Backupper is not only a cloning software, but also a imaging software. Besides using it to clone EFI partition, you can also use it to backup the EFI system partition into an image backup file to have another layer of protection.