Hello everybody!
In this video I’m going to tell you about MBR and GPT hard disk types.
How to learn which type you’re using, how to convert MBR into GPT and vice versa with
Windows standard tools, why you may need it, and what are the consequences of such conversion.
I’ll also show you which software to use for conversion without data loss.
They are two methods of storing the partition table on a hard disk.
GPT is a newer standard created for disks with capacity over 2 TB and required for booting
Windows in UEFI mode.
On the contrary, MBR is an older type which only allows creating up to 4 partitions on
disks under 2 TB.
It is required to boot old versions of the operating system - older than Windows 8.
You can learn which one - BIOS or UEFI - you’re using by pressing the key sequence Win+R:
in the window that opens type the command msinfo32, and you can see this information
in the window that opens next, in the BIOS version/date line.
How is the partition table used?
To see what system of partitions your hard disk is using, right-click on the Start menu
and select Disk Management.
Then right-click on the necessary disk and select Properties, then go to the tab Volumes
and in the line “Partition Style” you will see either Master Boot Record (MBR) or
GUID Partition Table (GUID) which is actually the GPT.
You can also see it by running the command “diskpart” in the Command Prompt.
To do it, type “cmd” in the search field, right-click on the Command Prompt and select
to run it as Administrator.
Enter “diskpart,” and then “list disk.”
As a result, you’ll see a table with information on the disks; if the disk is using GPT it
will have an asterisk, if it’s using MBR, the column will be empty.
For example, disk 0 is using MBR, and disk 1 – GPT.
How to convert MBR into GPT There are several ways to convert a hard disk
from MBR into GPT and vice versa with Windows tools.
The first is to enter Disk Management by right-clicking on the Start menu, selecting the necessary
disk, right-clicking on it and choosing the line “Convert to GPT disk.”
The disk for such conversion should have no partitions, otherwise the function will be
unavailable - just like in my case with disk 1: it’s inactive.
To convert such disk, you’ll have to delete all partitions to make the function available.
I delete the volume, and now conversion option is active.
Click “Convert to GPT disk”, then click on the disk and select “New simple volume”,
Next, if you check the box “Don’t format the volume” then after the operation the
disk will not be available and the system will suggest to format it.
That’s why don’t change anything here, just click Next and Finish.
That’s all, the disk has been converted into GPT, but as you have noticed, all the
information was deleted, so before you convert a disk, you should copy important data to
another disk.
The other method for conversion involves the Command Prompt; this way, you also delete
partitions, and the information will be lost.
Run the Command Prompt as Administrator, then enter the command “diskpart,” press Enter,
then “list disk,” then “select disk” and the number of such disk to be converted
- in my case that’s disk 1, then “clean,” and after this command all data will be removed
from the disk so be careful when choosing the disk for conversion.
Then enter the command “convert mbr” or “convert gpt” depending on what kind of
disk you want in the end.
After you’ve converted the disk with the Command Prompt, you should format it with
Disk Management.
“New Simple Volume” Both of the
said methods convert a disk from MBR to GPT and vice versa, but the information on the
disk will be lost.
Spanned volume In Disk Management, you can also create other
volumes, for example, spanned, striped or mirrored, but for this purpose, you need at
least two disks A spanned volume joins free spaces in several disks into one logical disk.
If you need more space than one of your disks can provide you can expand it with the free
space in another disk.
The advantage of spanned volumes is good isolation of failures, easy capacity planning, and direct
analysis of performance.
A striped volume provides quicker data access than with simple or spanned volumes.
The more disks you combine the higher is the bandwidth, but the reliability will become
less.
Loss of any of the disks within the combination will mean losing more data than you would
lose in a simple or spanned volume.
A mirrored volume creates a copy of the information on the second disk.
To create a volume of a certain type, select it from the list, Next, choose the disks,
Next, assign the drive letter, Next, Ready, Ок.
As you can see, I’ve created a striped volume consisting of four disks.
Theoretically, performance of such a combined disk should grow fourfold.
But now let’s go back to converting.
Why we need it?
For example, when installing Windows 7, you can face an error: “Windows cannot be installed
on this disk.
The selected disk is of the GPT partition style.”
In this case, the method using the command prompt will come in handy.
During the installation, when you see the word “Install,” press the key sequence
shift+F10 to start the Command Prompt, and use it to convert the disk into the required
type as I have shown before.
After the conversion, you should go to UEFI, the “boot” section, and disable Secure
Boot, then enable Legacy Mode or CSM depending on the version, and the error will go away.
The easiest way for conversion is doing it with the installer.
While you are installing the operating system, go to disk settings, remove all partitions
and create them again without using the command prompt.
In this case, the disk will be created with the MBR table but it is true only if your
disk is no bigger than 2 TB; if it has more capacity than that, this operation will create
a GPT table again.
As I have already said, the information will be lost.
Another error you may see when installing a new operating system is “Windows cannot
be installed on this disk.
The selected disk has an MBR partition table.
On EFI systems, Windows can only be installed on GPT disks.”
In this case, you should modify UEFI settings.
In the settings, find the section “boot” and disable “Secure Boot” there, then
enable “Legacy Mode” or CSM depending on the version of the operating system, and
the error should be fixed.
Converting disks without losing data There are a number of programs to convert
MBR into GPT and vice versa without loss of data.
My choice is AOMEI Partition Assistant, and you can see there’s some data on my disk
D. I start the program, click on the necessary disk, right-click, select “Convert to GPT
disk,” OK.
To start the process, click “Apply” and “Proceed” in the window that opens.
When the operation is over, you will see a window saying “Congratulations” All operations
have been completed successfully.”
Click OK.
As you can see, the disk has been converted into GPT, and all the information was preserved.
The program can easily convert the system disk as well; now I’m going to convert my
system disk and show you the final result.
Click on the system disk “Convert to GPT disk”, OK, Apply.
The system will be converted after the restart.
After conversion, my system didn’t boot.
In order to make it happen, go to UEFI and modify some settings.
I’ll show you which settings you should change, with the example of a Dell motherboard.
Find the section “boot” and change Legacy to UEFI, then click “Add boot options,”
specify the name and path to the EFI bootloader file and click Ок.
Select the bootloader as the first priority item, then Save Settings and Exit, and after
that my operating system booted successfully.
As you can see, the system disk was converted without losing data.
However, before you do it, save important information to another disk to prevent data
loss as results of using such software are sometimes unpredictable.
That is all for now.
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Thank you for watching.
Good luck.