How can I configure a UEFI motherboard for MBR instead of GPT?

[marisa69]

My new upgrade box (with no OS) has a EUFI motherboard.

I just did a test install of W7 (on an old HDD) and it ended up with GPT partitioning.

I don't want that, I want MBR. (And if you don't mind, I don't want to get into a discussion about WHY I want to do this. Thank you).

Does anyone know (and can explain in words of no more than two syllables to this old girl) which settings in UEFI I need to change?

I already have an idea it might be something to do with 'Secure Boot', and maybe 'CSM', but the complexities of UEFI are very confusing.

Thank you very much

 

[AddRAM]

Go into the Bios, there should be an option to enable Legacy or Legacy & UEFI

Once you enable that, hit F10 to save and exit.

If you now have a GPT disk, you will have to convert it back to MBR

http://www.sevenforums.com/tutorials/26203-convert-gpt-disk-mbr-disk.html

 

[teckneeculler]

AddRAM, I think there might be a bit more required than just changing Boot to 'Legacy' or 'Legacy + UEFI'.

For example, see this link:

https://technet.microsoft.com/en-us/library/hh825112.aspx

"To use BIOS-compatibility mode, check for options in the firmware menus to disable UEFI SecureBoot features."
"If you install Windows by using Windows Setup or the Windows installation DVD, use a preformatted hard drive on your destination PCs. Use the GPT file format for UEFI mode, or the MBR file format for BIOS mode."

"UEFI: To prevent Windows Setup or Windows PE from booting in BIOS mode, remove the bootmgr file on the root of the media.
BIOS: To prevent Windows Setup or Windows PE from booting in UEFI mode, remove the efi folder on the root of the media."

Also, someone on Tom's Hardware said:
"...if you mount a disk that's already been formatted in MBR, the OS install will be MBR."

Which was also said above in the first link

 

[Nipax]

If you now have a GPT disk, you will have to convert it back to MBR

http://www.sevenforums.com/tutorials/26203-convert-gpt-disk-mbr-disk.html

If you delete all the partitions you don't need the convert.

Boot from the Windows install media. Select the custom install option and delete all the partitions on the HDD.

Installing to the unallocated space and letting Windows create the partitions works with either GPT or MBR mode.

 

[marisa69]

Nipax, it would be nice if it were that easy.

If you read my first post again, you'll see that installing to an empty, unallocated hard drive was exactly what I did.

And the partition ended up GPT.

 

[ThrashZone]

Hi,
What size is the hdd ?
What is the mother board ?
Use the link above my signature to fill in your system spec's page

I doubt secure boot has anything to do with the issue you seemed to have installed without any issue except the hdd format.
Which points to a larger than normal sized hdd you installed windows on and you possibly made a smaller partition to install windows on :/

 

[Nipax]

How do you select GPT or MBR when installing Windows 7/8/10.

Windows 10 partition installs? - Windows 10 Forums

 

[marisa69]

TrashZone, the drive was a 120GB SATA that had been bare-metal cleaned with WipeDrive Pro 3.02.

Nipax, that's exactly my question, "How do you select GPT or MBR when installing Windows 7/8/10". Except I have no interest in Windows 8 or 10. Windows 7 will do me nicely until 2020, at which time I'll think again.

 

[ThrashZone]

I can't see how any of that tenforums stuff applies here
Is this a samsung computer or drive ?
Obviously this program to wipe the drive did not do such a good job there's no reason a 120gb drive would be gpt.

 

[GEWB]

See if this link helps:

https://technet.microsoft.com/en-us/library/cc725797.aspx

Regards,
GEWB

 

[GEWB]

You might also use a live Linux disk (Puppy Linux, Mint Linux, etc.) and use it to create an MBR formatted hard drive then fresh install Windows to it.

Regards,
GEWB

 

[Nipax]

How to convert disk from MBR to GPT or GPT to MBR if you do not want to keep the existing partition style.

Convert MBR to GPT:
1. Boot from the Windows 7/8/10 USB/DVD in UEFI mode.
2. Delete all partitions on the disk until it's unallocated.



Convert GPT to MBR:
1. Boot from the Windows 7/8/10 USB/DVD in Legacy BIOS mode.
2. Delete all partitions on the disk until it's unallocated.



Installing to the unallocated space and letting Windows create the partition table and partitions works with either Legacy BIOS or UEFI boot mode.

On an MBR disk, Windows 7/8/10 setup will create a System Reserved partition and a primary Windows partition.

On a GPT disk, Windows 7/8/10 setup will create a Recovery partition (not in Windows 7), an EFI System partition, a Microsoft Reserved partition (won't show in Disk Management), and a primary Windows partition.

 

[teckneeculler]

Great post, Nipax, clear, succinct, makes sense.

I'll save the page for future reference.

Well done

 

[ThrashZone]

Yep good post indeed but it also confirms the wipe program used did a crappy job at wiping the disk :/
If the bios is set to uefi only though could indeed be the issue.

 

[marisa69]

Thank you, Nipax, I think your information has answered my question.

And thank you everyone else who made POSITIVE contributions

Happy Hogmanay!