By AOMEI / Last Updated June 24, 2021

When will we meet with this situation?

There are many discussions about this in PC forum. Now I take some for examples:

  • "I'm trying to install Windows 7 on a separate 100GB partition beside my Windows 8 partition (dual boot). The disc boots fine, but I can't select my partition (Disk 0 part 5) because of the error: "The selected disk is of the GPT partition style".

  • "I tried to install Windows Server 2008 R2 on my partition. When I select the partition, I got the error message: "Windows cannot be installed on this disk. The selected disk is of the GPT partition style".

  • "While trying to Wipe Windows 7 and install Windows 8 on my Zenbook, I have encountered an annoying error message: 'Windows cannot be installed to this disk. The selected disk is of the GPT partition style'. No other information is given."

Now we see people will come to the question about "the selected disk is of the GPT partition style" when they reinstall Windows system. Before we analyze this problem, we have to clarify some definitions. First, we need to know that there are two partition styles: GPT and MBR.

About GPT and MBR

MBR and GPT are the format of hard disk. MBR is the abbreviation of master bootable record, and it only supports the maximum capacity with 2TB, up to four primary partitions, or three primary partitions plus one extended partition. Most of personal computer’s motherboard only supports BIOS and it is installed with MBR, so, for many users, they always install windows system on the MBR disk.

GPT is abbreviation of GUID partition table. It is a part of EFI, which is port between operating system and platform firmware. GPT can make use of a very large space that is more than 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.

In terms of the description above, it seems that GPT disk is better than MBR, Unfortunately, the seldom of computers have EFI motherboard, not even mention make use of GPT disk. In the context of specific case, that may be the greatest of shortages in GPT disk. As mentioned above, many people can’t install windows system on GPT disk.

Why does such question happening? Based on what we analyze above, in order to boot Windows from GPT, our motherboard should support UEFI (EFI-boot & BIOS-boot), otherwise we should use MBR to boot from. More information please visit:

How to Solve This Problem with the Simplest Way?

Notice that I said "the Simplest Way". Although there are many solutions we can find from the forum, I’d like to suggest you use the simplest way: convert GPT to MBR disk.

Convert GPT to MBR with Diskpart

In some technology or computer forum, some technicians give some advice that convert GPT to MBR with Diskpart, which is run by program code. The specific steps are following below:

  • Enter system installing interface by using Win 7 disc or USB hard drive boot. and then press “Shift”+”F10” to open the command prompt.

  • Input “Diskpart” (do not input quotation mark, the following as well), and then press “Enter”to enter operating interface.

  • Input “list disk”: to check hard disk properties. Pay more attention to capacity of hard disk to select. Usually, disk 0 is hard disk, and disk 1 is the usb dirve where wins 7 install.

  • Input “select disk 0”: to select disk 0 as the disk that is operating.

  • Input “clean”: to clean up current hard disk’s partition.

  • Input “convert mbr”: to convert GPT into MBR.

  • Input “create partition primary size = xxx”: to create the size of primary partition.

  • Input “format fs = ntfs quick”: to format disk to NTFS quickly.

  • Input “exit”: to finish operating.

  • Input “exit”: to shut down the command prompt.

After finishing operating, shut down the command prompt and install windows system on computer in normal way. The steps seems be concise, but the greatest shortage is that all data and files will be clean up. If you don’t have backup files in GPT disk, you will be crying and anxious for that. And if you don’t have some professional knowledge about program, this way is not recommended.

Convert GPT to MBR with the third-party software

To some users who is a lack of computer professional knowledge, it is a good way that convert GPT to MBR with a third-party software. Of many kinds of third-party software, AOMEI Partition Assistant is a not bad tool to help user to convert disk. It’s the greatest strengthen is to convert disk from GPT to MBR without data loss.

How? With the help of AOMEI Partition Assistant Professional Edition, it is easy to do. Because AOMEI Partition Assistant Professional Edition has a powerful feature named “Convert GPT to MBR or MBR to GPT”. Step by Step Guide to convert GPT to MBR:

Step 1. Download, install, and launch AOMEI Partition Assistant. (see picture, below)

Step 2. Select the disk we want to convert, right-click and select “Convert to MBR Disk”.

Convert System Disk to MBR

Click “OK” in the pop-up window:

OK to MBR System Disk

Step 3. Back to the main menu, we can see the pending operations and click “Apply” to commit the changes.

Apply to MBR System Disk

Wasn't this process a piece of cake? With this powerful partition converter, we can optimize our partition easily. We can convert primary to logical partition, convert FAT/FAT 32 to NTFS, migrate OS to SDD and so on. We can even make a portable Windows 8 by using the function of “Windows To Go Creator”. What’s a powerful disk partition converter it is!