When you install Windows on your disk, you may be reminded that “The Windows cannot be installed in this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disk”. That means the your computer is currently booted in UEFI mode, but your hard drive is not configured for it. To put it simply, when you are trying to install Windows 10 on MBR partition in UEFI mode, it will fail. So, when you receive the error, you have to convert the disk from MBR to GPT so that the whole progress can work normally.
So you may have questions about MBR and GPT, like “What is MBR or GPT? What makes them different? ”, and so on. MBR (master boot record) and GPT(GUID partition table) are two types of partition styles. MBR disk usually is used in a traditional computer. While nearly Windows 8 or Windows 10’s default disk is GPT. Besides the above situation, there are many other reasons why you need to convert MBR disk to GPT.
> MBR disk supports up to 2TB volume of a hard disk. Thus, if the hard drive is larger than 2TB, it cannot be used totally - the volume beyond 2TB will be shown as unallocated space and you cannot operate on it, unless you convert the MBR to GPT because GPT disk breaks out the 2TB limitation of MBR disk. It supports up to 18EB.
> On MBR disk, you are allowed to create 4 primary partitions in maximum. If you need more partitions, you have to turn one primary partition into an extended partition so that you can create logical partitions without limitation, or you can convert the MBR disk to GPT because GPT disk has no limit of how many primary partitions on.
How to convert MBR to GPT using CMD without data loss?
To convert MBR to GPT, the most common tool is Command Prompt. However, is it possible to convert MBR to GPT using CMD without data loss? As we all know, it is necessary to delete all existing partitions on the target disk before conversion. So, the most effective way to avoid data loss during conversion is to make a backup in advance. Or you can use the MBR2GPT.exe tool to convert MBR to GPT without data loss. 2 Methods are listed with most details below.
1. Convert MBR to GPT with DiskPart tool
Back up the disk ahead of time to ensure no data loss during the MBR to GPT conversion using DiskPart command.
1>. Press Win+R key to open Run dialogue box and input cmd to launch thecommand prompt window.
If you need to convert a boot disk, you have to do as following to open the CMD window.
Using Windows installation disc or any bootable media created before to get into the system installing interface.
Press Shift + F10 to open the command prompt.
2>.Type in Diskpart, and press Enter key.
3>. Type list disk to view the disk information.
4>.Type select disk n to select the disk that needs to be converted in GPT.
5>. Type convert gpt to convert the select disk into a GPT disk.
2. Convert to GPT via MBR2GPT command without data loss
Windows 10 v1703 and later versions comes with built-in MBR2GPT tool, which is able to convert an system MBR disk to a GPT disk without modifying or deleting data on the disk. It runs from a Windows Preinstallation Environment (Windows PE) command prompt, but can also be run from Windows 10 operation system by using the /allowFullOS option.
1>.Boot computer from the bootable media and press Shift+ F10 in the Windows Setup window to open Command Prompt window.
2>.Then input the following two commands in turn and press Enter after each one.
3. Convert to GPT with Disk Management
If you're not familiar with CMD commands, you can also turn to Disk Management.
1>. Right-click on "This PC", choose "Manage", then head to "Disk Management".
2>. Right-click the volumes on your target disk and choose "Delete Volume..."
3>. When your disk becomes empty (shows as unallocated space), right-click your disk and choose "Convert to GPT Disk".
Easiest way to convert MBR to GPT without data loss/deleting partitions
So, to convert MBR to GPT using CMD without data loss, you have to back up the disk ahead of time. Though the MBR2GPT command can convert MBR to GPT without losing data, it is only availabe for system disk. Now, we would like to share you with the best way to convert both data and system disk from MBR to GPT without data loss. That is using AOMEI Partition Assistant Professional, a professional hard disk manager that allows you to convert a disk between MBR and GPT without losing data easily.
1. The whole operation will not delete any partition or data on the original drive, but in case of other unexpected situations happens may cause data loss, we suggest you’d better back up data in advance.
2. If you are converting system disk to GPT disk, you need to make sure that the computer supports EFI/UEFI. After converting, you need to get into BIOS and switch from Legacy to EFI/UEFI so that you can boot computer from converted GPT disk successfully.
AOMEI Partition Assistant Professional provides you the easiest way to convert MBR to GPT without losing data - its GUI with mouse-clicking.
Step 1. Launch AOMEI Partition Assistant Professional. When you see the main interface, choose the disk you want to convert to GPT (AOMEI Partition Assistant Professional allows you to convert MBR to GPT disk no matter it is a system disk or disk without a system installed on it). Right-click on it and select Convert to a GPT.
Step 2. It will pop up a window that you need to confirm. Click OK and you’ll be back to the main interface.
Step3. Here you can see that the disk has been converted into GPT, but it’s not the end. You need to click Apply at the toolbar to execute the task.
Now, you should know how to convert MBR to GPT using CMD without data loss in Windows computer. Obviously, the AOMEI Partition Assistant provides the easiest and safest way to convert MBR and GPT partition style. It allows you to finish MBR and GPT conversion directly without deleting any partition or data. Besides this features, it is also able to clone MBR disk to GPT disk, recover lost partitions, migrate OS between MBR and GPT hard drive, etc.
FAQs about converting MBR to GPT using CMD
Can I convert MBR to GPT using CMD without losing my data?
Yes, it's possible to convert MBR to GPT using CMD (Command Prompt) without data loss, but it's crucial to back up your data before attempting the conversion. Although the process itself doesn't inherently erase data, unforeseen errors can occur, so always have a backup.
What are the prerequisites for this conversion?
Before you begin, ensure that your system is running a 64-bit version of Windows and that your data is backed up. Additionally, your hard drive should be in good health, without any errors or bad sectors.
Can I convert from GPT to MBR using the same method?
Unfortunately, converting from GPT to MBR without data loss is more complicated and typically requires deleting all partitions and starting fresh. This process will result in data loss, so be cautious and back up your data before attempting it.
Can I convert my system drive from MBR to GPT?
Yes, you can convert your system drive from MBR to GPT, but it's a more complex process that involves additional steps to ensure your system remains bootable. It's strongly advised to consult a professional or follow a comprehensive guide for this task.