Convert GPT to MBR or Convert MBR to GPT Disk without Losing Data
About MBR and GPT Disk
What are the limitations of MBR disk?
MBR disks only support up to 2TB partition size and support only four primary partitions. If more partitions are needed, you have to build a secondary structure known as extended partition, and then you can create logical partitions. MBR partitioning rules are complex and poorly specified.
What are the advantages of GPT disk?
GPT disks can make use of a very large size to break the 2TB limit of MBR disks. GPT disks allow an almost unlimited number of partitions. Each GPT partition has a unique identification GUID and a partition content type. And you can have more primary partitions. However, the Windows implementation restricts this to 128 partitions.
Why do you need to convert MBR/GPT?
As mentioned above, MBR disks only support up to 2TB partition size, so if you have a disk which is MBR formatted and larger than 2TB, you could only use 2TB disk size among it, but the rest of it could not be used. Converting MBR disk to GPT disk is considerable necessary to make full use of the disk space.
On the other hand, since Windows 95/98/ME, Windows NT4, Windows 2000, Windows 2003 32-bit, or Windows XP 32-bit version does not support GPT partitions. A GPT disk will display as GPT protective partition in these systems, thus you could not access the data until you convert them back to MBR disk. But note if you want to convert any larger than 2TB GPT disk back to MBR disk, you'd ensure that the data does not account for space more than 2TB.
Before you do
The following tutorial applies to convert data and system disk between MBR and GPT styles. However, if you want to convert system disk between MBR and GPT styles, please change boot mode between UEFI and Legacy after conversion is completed.
Because of the limitations of MBR disk, therefore if there are more than 4 partitions on GPT disk, this program cannot convert GPT to MBR disk unless you delete some unused partitions; if you want to convert a GPT disk larger than 2TB back to MBR disk, you should ensure that the data does not account for space more than 2TB.
How to do the conversion between GPT and MBR disks?
Download AOMEI Partition Assistant first, you can use the software: AOMEI Partition Assistant Professional Edition or Server Edition to realize this conversion.
Step1: Launch AOMEI Partition Assistant. Select the data disk you want to convert and right click it. And then select "Convert to GPT Disk" (or Convert to MBR Disk) in the drop-down menu.
Step2: Click "OK" after confirming the operation.
Step3: You can preview the conversion. To save the change, please click "Apply" on the toolbar.
For system boot disk conversion between MBR and GPT styles, to guarantee system bootable, you need to enter BIOS and change the boot mode after the conversion is completed.
For conversion between MBR and GPT disks on Laptop, please make sure the power supply is sufficient.
To ensure the data is consistent, do not abnormally terminate the program during the conversion process.