[Solved] How to clone Windows from GPT disk to MBR disk for free?

November 22, 2022, Posted by Admin to Free Disk Cloning Software for Windows

This tutorial mainly describes how to use Hasleo Backup Suite to clone Windows from GPT disk to MBR disk, and also introduces some knowledge related to cloning Windows from GPT disk to MBR disk, as follows:

Overview and principles of MBR

The full name of MBR is Master Boot Record, it was introduced in IBM PC DOS 2.0 in 1983. It is called "Master Boot Record" because it is a special boot sector present at the beginning of the drive, which contains the boot loader of the installed operating system and the logical partition information of the drive, and the specific structure is as follows:

OffsetSize (bytes)Description
0x000440Boot code (flat binary executable code)
0x1B84Unique disk signature
0x1BC16First partition table entry
0x1CC16Second partition table entry
0x1DC16Third partition table entry
0x1EC16Fourth partition table entry
0x1FE2End flag(0x55, 0xAA)

From the table above we can see that MBR can only describe up to four partitions, however in reality we may need more partitions. To solve this problem, MBR introduces the concept of extended partition, usually the last entry in the partition table entry of the MBR points to the extended partition. The structure of the extended partition is as follows:

extended partition

As shown above, the extended partition use the Extended Boot Record (EBR) to describe partitions, the previous EBR points to the next EBR, so multiple partitions can be described, which are called logical partitions.

MBR uses partition table entries to describe the partitions on the disk, the partition table entry is structured as follows:

OffsetSize (bytes)Description
0x001Drive attributes (0x80: active partition)
0x013CHS Address of partition start
0x041Partition type
0x053CHS address of last partition sector
0x084LBA of partition start
0x0C4Number of sectors in partition

We can see that the partition table entry uses 4 bytes to describe the starting sector number and number of sectors of the partition, so MBR can only address disks up to 2 TB (2 ^ 32 x 512).

Overview and principles of GPT

GPT is short for GUID partition table, it is a part of the EFI standard that defines the layout of the partition table on a hard drive. Due to the rapid growth of hard disk capacity, MBR can only describe 4 primary partitions and 2.2T capacity is difficult to meet the requirements, in order to solve these problems, GPT came into being, and the promotion of UEFI BIOS laid a solid technical foundation for GPT. In GPT, all partition information is saved in the GPT header, and the first sector of the disk uses the same structure as MBR (usually called Protective MBR), and the operating system can determine whether the disk is an MBR disk or a GPT disk through the information in the Protective MBR. The structure of the GPT is as follows:

gpt partition cheme

Protective MBR: There is a partition table entry with partition type 0xEE in the Protective MBR of the GPT disk, which is used to distinguish whether it is a GPT disk or a MBR disk.

Primary GPT header: The primary GPT header stores information such as the unique disk GUID (used to uniquely identify a GPT disk), CRC (cyclic redundancy check) of GPT header and partition table, the number of partition table entries, and the start LBA of the partition table entries array.

Partition table entry: It is used to describe a partition on the disk, including the partition GUID, start LBA and end LBA, as follows:

OffsetSize (bytes)Description
0x0016Partition type GUID
0x1016Unique partition GUID
0x208First LBA
0x288Last LBA
0x308Attribute flags (read-only, hidden, etc.)
0x3872Partition name

Backup partition table and GPT header: They are backups of the primary partition table and GPT header, used to restore GPT if the primary partition table or GPT header is lost or corrupted.

Why clone Windows from GPT disk to MBR disk?

Above we have detailed MBR and GPT, and it is very clear that GPT has greater advantages than MBR, so under what circumstances may we need to convert Windows running on GPT disk to MBR disk? The answer is if you want to clone a Windows running on a modern UEFI-based computer to another disk, and then run the cloned Windows on a traditional BIOS-based computer.

 

Tutorial to clone Windows from GPT disk to MBR disk with Hasleo Backup Suite Free.

Step 1. Download, install and run Hasleo Backup Suite Free.

Download Best Free Windows Backup Software for Windows

Step 2. Click "Clone" button in the navigation bar, then click "System Clone" button in the operation area.

click system clone
 

Step 3. Hasleo Backup Suite will automatically select all partitions that need to be cloned for Windows operating system clone, just click "Next".

system clone select source disk
 

Step 4. Select the destination disk you want to clone the Windows operating system to and tick the "Clone as MBR" option, then click "Next".

system clone select destination disk

Step 5. Adjust the size and location of the partitions according to your needs, then click "Proceed". A warning message may pop up to tell you that all data on the destination drive will be destroyed, click the "Yes" to continue if you do not have important data on the destination disk.

system clone adjust partitions

* Disk alignment:

  1. 1M (Recommended): 1M alignment is a subset of 4K alignment, and partitions aligned by 1M are always 4K alignment, so it can help you get the best performance of an SSD. In Windows Vista and later OSs, partitions created using Windows Disk Management always aligned by 1M bytes, regardless of whether the disk is an SSD.
  2. 4K: Ensure that the start sector of each destination partition is always aligned by 4K bytes, which is very important for the best performance of an SSD.
  3. Cylinder: Ensure that the start sector of each destination partition always starts at the beginning of a cylinder. Windows XP and previous OSs use this alignment mode.
  4. None: The start sector of each destination partition is not aligned.

* The Sector by sector clone partiton option enables you to clone all sectors from source partition to destination partition.

Step 6. Hasleo Backup Suite starts cloning the Windows operating system to the destination disk. Please note that the time required for disk cloning is related to the size of the data that needs to be cloned, so please be patient.

disk clone progress

* If you don't want to wait until the operation is finished, please check the "Shut down the computer when the operation is completed" checkbox.

Conclusion

As mentioned above, you can easily clone Windows from GPT disk to MBR disk with the help of Hasleo Backup Suite, and you can clone GPT disk to MBR disk with the disk clone feature of Hasleo Backup Suite.

As a professional Windows backup and cloning software, you can not only use Hasleo Backup Suite to clone Windows from GPT disk to MBR disk, but also restore GPT Windows system backup image to MBR disk, or clone Windows from MBR disk to GPT.