About Contribute Disclaimer Contact News
The information on this site is offered in good faith and no responsibility can be accepted for misuse that leads to loss of data or damaged hardware.
Help Us Improve
Have you spotted an error, or found something confusing or ambiguous? Help us improve our articles......

Google Advert Links
spacer Multibooters.com

hard drive style button graphic

How to Determine if a Hard Drive is Configured
With the MBR or GUID Partitioning Schemes.

The partition style of a hard drive will not only dictate how we handle partitions, but also which operating systems we can install and which tools and bootmanagers can be used.

MBR or GPT.   The new GUID Partition Table (GPT) that is set to take over from the classic MBR (or msdos) partition table will literally re-write the rule book on how to configure and manage a dual or multiboot computer. Many of the current utilities and apps that have been around for years will be unsafe to use so it really is important that we determine how a hard drive has been styled before attempting any work or modifications to its underlying setup. For an introduction to partition style and a couple of other factors it is crucial to be aware of we suggest you have a look at our page...info iconFormat, Style and Type.

The new GPT way of partitioning a hard drive was designed in tandem with a new type of BIOS on the PC motherboard, so with store-bought machines the chances are that if you have one you also have the other. The new UEFI (Unified Extensible Firmware Interface) replaces the old BIOS firmware which is only capable of booting an MBR styled hard drive. On Windows machines if you only have one hard drive and it is GPT then you almost certainly have a UEFI capable motherboard to allow you to boot from that drive. info iconDetermine if a Machine is UEFI or BIOS

View the hard drive in Windows Disk Management.

The Disk Management utility in new generation Windows can be used to show us the partition style a hard drive vista-7-8 logoshas been configured with. In our example below we have more than one drive and only the second drive is GPT. When you open Disk Management there is no immediate clue to this fact and no obvious difference between the two styles of hard drives.

Fig: 1disk management screenshot

If you right click in the gray area to the left of the bar graphic for a drive you will receive a popup menu. The list of options here can vary across Windows versions and editions but the option we have highlighted should be present in all Windows-7/8 and some editions of Vista. The option will say the opposite to what the drive currently is, so if as in our example it reads MBR then the disk is presently configured to be GPT, (the option will be grayed out if there are existing partitions on the drive as only unpartitioned disks can be converted).

Whether the convert to MBR/GPT option is present or not, clicking the Properties option will open a dialog box called Device Properties (fig:2) where if you select the Volumes tab you will see specific details of the selected hard drive with the Partition Style clearly listed as GUID Partition Table (GPT) or the alternative Master Boot Record (MBR).

Fig: 2
disk management screenshot

Note that 32-bit XP never had any support for GPT and will incorrectly show them as being MBR. You can also get to this Device Properties dialog box through Device Manager, where you select the Disk Drive you want to look at and right-click on it and select Properties and when on the Volumes tab press the extra Populate button.


If we want to look at more than one drive at a time we can choose to have Disk Management display a list of drives in its top pane as opposed to the list of all partitions that it does by default. On the main tool bar click View and point to Top and then click Disk List (fig:3).
diak management screenshot


The disk view shows all the partitionable drives and devices that are currently connected to a machine. In our example (fig:4) there are three internal hard drives, with the boot drive styled as MBR and the other two in the GPT partition style.
Fig: 4
disk management screenshot
GPT styled drives can be used as data drives in BIOS based machines as long as the boot drive is MBR and the operating system is GPT aware and can therefore see and use the GPT drive. It is not natively possible to install Windows to a GPT drive in a BIOS only machine, or to have Windows 32-bit on a GPT drive, but the eagle-eyed of you out there may have spotted that the screen shot we have used here from one of our test rigs seems to be showing both those things. See..... info icon Running Windows from a GPT drive in a BIOS PC.


Windows XP and GPT hard drives.

Only the 64-bit version of Windows XP can fully recognize and work with a GPT configured hard drive. The Disk Management utility will report the same as the one in Vista, but the 32-bit XP can do no more than inform us that we have a GPT drive by detecting the presence of what is called a GPT Protective Partition. This partition that appears to span the WInXP logoentire drive is really just a phantom that has been defined in a dummy MBR partition table that is the only thing retained on the first sector of the drive for the sole purpose of trying to prevent an MBR partitioning tool that knows nothing of GPT from overwriting existing GUID partitions.

Fig: 5
xp disk management

The Disk Management tool in 32-bit XP is GPT aware enough to recognize the protective partition but is not capable of creating or working with GPT partitions or drives and therefore will not allow any tampering with a GPT drive.


Third Party Partitioning tools.

Most of the actively maintained third-party partitioning tools out there are now fully GPT aware and capable, but there are still some that are only aware enough to recognize the existence of the protective partition and so block any messing with a GPT styled drive. There are of course numerous older tools still available and in use that know nothing of GPT or protective partitions and so could unwittingly be used to destroy data on a GPT drive. Such tools will happily let you delete the protective partition and create MBR partitions over the top of the existing GPT partitions, thereby corrupting those partitions and their data. Below are screenshots from a few GPT capable partitioning tools.
Disk Wizard screen shot


screenshot Gparted


Paragon's Partition Manager - http://www.paragon-software.com/home/
PM11 screenshot


gnome-disk-utility - already present inside many of the user friendly Linux distros we recommend,
but is available for any Linux-based operating system. https://git.gnome.org/browse/gnome-disk-utility/
Linux Disk Utility screenshot


Spanner icon
bootscreen thumbnailGparted
Tech Bench
For the more computer able amongst us.
Those who are familiar with the Windows command line can use the Diskpart tool to see if drives are GPT styled. The single command list disk will display a list of disks connected to the machine and give a very limited amount of info about each disk. The last column is Gpt and an asterisk here informs that the disk is partitioned in the GPT style.



multibooters logo multibooters.com
creative commons licence

All product and company logos, icons and images that are reproduced on this site are the property and trademarks of their respective owners and are used here merely to illustrate their products, NOT to indicate or infer any endorsement or partnership unless otherwise stated. We have endeavored not to reproduce copyrighted images or graphics or infringe upon the rights of any trademark or copyright holder. If you believe or suspect we may have breached the permissible use of copyrighted material then please bring it to our attention. The reproducing or copying of original material from this site is currently allowed for non commercial purposes with the provision that your source is clearly indicated and that a back-link to the referenced information is included. Thank You. See our full  Terms of Use.  Material on this site is not guaranteed to be free of errors.   Multibooters.com   2012 - 2013

Home Sitemap Privacy-Policy About Contact/Feedback Donate Copyright/Legal