Creating a Legacy MBR Bootable USB with Windows 10

If, when trying to install Windows 10 from a flash drive, you encounter an error message stating that installation on the selected disk or partition is impossible due to the presence of an MBR partition table, or you have a computer with a legacy BIOS boot mode instead of a modern UEFI, this article will help you create Windows 10 bootable USB drive to MBR legacy disk for you.
The essence of the problem is that the system is configured in UEFI mode, and the disk uses the outdated MBR (Master Boot Record) partitioning system, while the modern GPT (GUID Partition Table) is required. This may be because your computer has been around for a long time, and modern systems operate according to new standards. A possible cause may be a previously installed Windows 7 or XP, as well as a replacement hard drive.

Briefly about MBR and GPT

There are two predominant styles of partitioning data on a disk – MBR (Master Boot Record) and GPT (GUID Partition Table). Both serve the same purpose – they indicate exactly how data is placed on disk. MBR, or “Legacy MBR”, is a legacy technology that was developed a relatively long time ago. Its main drawback is the limitation of four primary partitions and support for disks up to 2 TB. The advantage is that MBR can be configured to work with almost all operating systems (GPT only requires modern systems that support the UEFI standard).
GPT is a modern solution. This format does not have the limitations of MBR, supporting up to 128 partitions per disk in Windows (and more in other OSes) and working with disks larger than 2 TB. The advantage of GPT is its higher level of reliability than MBR.

Is it possible to solve the problem by changing the MBR system to GPT?

To convert a disk from the old MBR style to the new GPT without losing data to install Windows 10, you can use built-in Windows tools (command line and diskpart) and special programs that can help. But, firstly, there is always a risk of data loss and you need to make a backup copy of it, and secondly, after changing the MBR style to GPT, the system, under certain conditions, may begin to require compliance with the UEFI standard. There is a simpler solution – creating a bootable Windows 10 USB drive with specified recording conditions for a disk with an MBR.

How to create a bootable usb from Windows 10 to MBR?

To create such a drive, we will use the Rufus program, due to its versatility and the ability to switch between MBR (BIOS) and GPT (UEFI). We reviewed the functionality of Rufus in this material. To create an ISO image of Windows 10 for recording on a bootable drive, the official utility from Microsoft – Media Creation Tool – will be used.

So, let’s go to the official Microsoft website to download the Media Creation Tool from Windows 10.

After downloading the utility, run it, read the license terms and click “Accept”.

In the next step, select “Create installation media” and click “Next”.

Select the language, version and architecture of Windows 10 and click “Next”.

At this step, select “ISO file” and click “Next”.

The utility will begin to create an image of the operating system in .iso format with the selected parameters.

When finished, the utility will notify you that the Windows 10 image has been successfully created. The path to the file location will be specified at this step.

Now let’s move on to working with Rufus. You need to download the latest version of the program from the official website.

Once the download is complete, open the program and insert the flash drive into a free USB port. The connected USB device should be displayed in the program section (Device). In the (Boot Selection) section, click on “Select” to select the created Windows 10 ISO image.

The next step is to select the “Partition Scheme” field, where we just need to select the MBR parameter. In this case, the field on the right will automatically change the value to BIOS (or UEFI-CSM), and the file system parameter located below will change to NTFS. After that, everything is ready and you can click “Start”.

The program will send a notification that all data on the drive will be overwritten and destroyed, and if you forgot something important on your USB, this is the last opportunity to save the data. If everything is in order, then click “OK”.

Rufus will begin creating a bootable flash drive. It does not take a lot of time.

At the end of the process, the “READY” status and the “CLOSE” button will appear. The creation process is complete.

You now have a bootable Windows 10 USB drive ready to use on MBR computers. To launch and install, restart your computer and select the USB drive as the first boot device in the BIOS or UEFI settings.
Using these steps and the help of Rufus, you can easily create a bootable USB for installing or restoring an operating system (in our case it is Windows 10), suitable for the MBR partition style.