Mbr to Gpt

Discussion in 'Windows 8' started by Ditbardh, Oct 3, 2012.

  1. Ditbardh

    Ditbardh MDL Novice

    Dec 26, 2011
    Hi all,

    I just bought windows 8 and i cant install it, its saying that i have mbr hard disk and i need gpt, how to convert to gpt, searched a lot in forum but havent found something that works, in bios havent found any option to use UEFI boot, this is what i get: Untitled.jpg
    my pc is lenovo m71e

    please help me, its urgent...
    thanks in advance.
  2. Ditbardh

    Ditbardh MDL Novice

    Dec 26, 2011
    yeah i saw this, but the problem is that i have only one hardisk not two :( ? thanks for help
  3. hbhb

    hbhb MDL Expert

    Dec 15, 2010
    Follow instructions and execute:biggrin:
  4. moderate

    moderate MDL Guru

    Aug 31, 2009
    #5 moderate, Oct 4, 2012
    Last edited: Oct 4, 2012
    How to create GUID GPT system startup disk with diskpart.exe (3 partitions are needed to create EFI, MSR, Primary)
    (connect the disk to already working W7 for a minute)
    if you are confused from following text, just message me for help :)

    Microsoft Windows [Verze 6.1.7601]
    Copyright (c) 2009 Microsoft Corporation. Všechna práva vyhrazena.


    Microsoft DiskPart verze 6.1.7601
    Copyright (C) 1999-2008 Microsoft Corporation.
    V počítači: JUNIOR



    list disk
    select disk[=n]
    detail disk
    list partition
    select partition[=n/l]
    detail partition

    clean [all]
    convert gpt [noerr]

    create partition efi [size=n] [offset=n] [noerr]
    create partition msr [size=n] [offset=n] [noerr]
    create partition primary [size=n] [offset=n] [id=byte/guid] [noerr]

    assign [[letter=l]/[mount=path]] [noerr]

    list disk


    A GPT-based drive might include the following partitions:

    An EFI System Partition (ESP)
    Each bootable drive must contain an ESP. The computer boots to this partition.
    For Advanced Format Generation One (4-KB-per-sector) drives, the minimum size of this partition is 260 MB.
    For earlier 512-byte-per-sector drives, the minimum size of this partition is 100MB.

    A Microsoft® Reserved Partition (MSR)

    We recommend that you add an MSR to each drive for disk management.
    The MSR is a reserved partition that does not receive a partition ID. It cannot store user data.
    The size of an MSR partition is 128 MB.

    Up to 128 primary partitions

    You can use primary partitions to store files and utilities.

    When initially created, the size of the MSR depends on the size of the disk drive:
    On drives less than 16GB in size, the MSR is 32MB
    On drives greater than or equal two 16GB, the MSR is 128 MB.

    As the MSR is divided into other partitions, it becomes smaller.

    The ESP is 1% of the drive capacity, or a minimum size of 100MB and a maximum size of 1,000MB.

    Create a GUID Partition Table Partition on a Raw Disk
    To create a GPT partition on a raw disk by using the Diskpart utility:

    At a command prompt, type: diskpart to start the Diskpart utility: "Diskpart version 0.0" is displayed as well as a Diskpart prompt.
    At the prompt, type: list to list the mounted hard drive volumes.
    At the prompt, type: select x (where x is the number of the hard disk drive that you want to convert to GPT). The following information is displayed: "Selected Disk = x".
    At the prompt, type: new gpt to add the GPT information into the non-volatile RAM (NVRAM).
    NOTE: This step does not create the GPT partition information.
    At the prompt, type: create name="efi system partition" type=efisys Size=102 to create the Extensible Firmware Interface (EFI) partition.
    NOTE: The name can be anything you want, but if the name has spaces in it, the name must have quotes around it. The type must equal either Efisys, Msres, or Msdata. If a size is not specified, the partition uses the remaining unpartitioned space. To install Windows XP, the Msdata partition must contain at least 2 gigabytes (GB) of free space.
    At the prompt, type: create name="microsoft reserved" type=msres Size=31 to create the MSR partition.
    At the prompt, type: create name="basic data" type=msdata to create a partition for the remaining unpartitioned space.
    At the prompt, type: inspect to display the partition information.
    At the prompt, type: exit to quit the Diskpart utility.
  5. Flipp3r

    Flipp3r MDL Expert

    Feb 11, 2009
    Is this an upgrade or clean install?
    If your going to wipe your drive it's easy.
    Boot windows 8 DVD.
    Press shift+F10 to get an administrator command prompt.
    Run diskpart

    sel dis 0
    con gpt
    cre par efi size=100
    for fs=fat32 label="System" quick
    cre par msr size=128
    cre par pri
    for fs=ntfs label="Windows" quick
    assign letter="W"

    Continue with the install...
  6. kamatayan

    kamatayan MDL Novice

    Oct 2, 2012
    mini tool partition wizard home edition (free) for windows and cd edition (iso file, burn to cd; free) can convert mbr partition to gpt.
    however, this will wipe out all data existing on the drive and may require UEFI to be ENABLED.
    activation via microsoft will proceed accordingly if using legit keys.
    activation via loaders will fail because loaders will activate windows only if the partition is mbr partitioned.

    if you wish to proceed, backup important files to another media (cd/dvd/usb flash drive/external hdd).
    wipe out contents of your hard disk drive using the tool, then install your favorite os in gpt.
  7. Ditbardh

    Ditbardh MDL Novice

    Dec 26, 2011
    hey guys im really thankful for the help, i made it and im going to write later how i made it, i think it can help others to.
  8. acyuta

    acyuta MDL Expert

    Mar 8, 2010
    Hi I just need an answer to this:

    1. I have a Dell XPS15 laptop (2011) with BIOS. I have recently bought a 1TB hard disk that I initialised as a MBR. However, I want to know if there are any issues in initialising it as GPT. The reasons for me do not include performance but rather that I can make 5-6 partitions for convenience instead for being restricted to 4 on MBR.

    2. Another related question. On my desktop (LGA, 2011, ASUS, UEFI, June 2012), all the 4-5 internal disks are initialised as GPT. This includes even SSD and 2Tb disks that do not need strictly be used as GPT. I know that I can create more than 4 partitions on GPT but have not done it. Do people here have created more than 4 partitions on GPT drive and has there been any issue (should not be).

    I have initialised all disks (incl. SSD, 2TB, 3TB, and 4TB) as GPT for the sake of system uniformity and using 3-4TB disks. I would also like to use GPT on my laptop even though it has a 1tb disk and so can work with MBR.
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  9. murphy78

    murphy78 MDL DISM Enthusiast

    Nov 18, 2012
    You don't need to have a GPT(UEFI) disk for Windows 8. I'm using Windows 8.1 on a MBR partitioned disk right now.
    I've no real problems with UEFI booting, but since Win8.1 has that secureboot nag and I like to dual-boot win7, I find it more advantageous to use MBR and BIOS booting.

    To use BIOS booting, you have to enable Legacy OPROM in your bios boot options.
    Then you also have to boot from a Windows Setup DVD or USB Flash drive while not using the one specified as "UEFI: xxxxxxxxxx"

    If you set up windows by booting from BIOS (Legacy booting) it will automatically format any unpartitioned drive to MBR and set everything up correctly.

    Also, if you boot into UEFI mode, it will automatically set it to GPT paritioning during setup.
    If you are having issues with it trying to format incorrectly, you're likely not booting to the correct setup boot option.
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  10. ODY123

    ODY123 MDL Expert

    Apr 20, 2011
    1. I also have a Dell laptop with 1TB hard drive, I had tried to format it as MBR and GPT before, but I prefer GPT over MBR with secure boot.
    2. I have 7 partitions on my 1TB hard drive, I have 3 60GB partitions for different OS, and 4 partitions for data.