Intel Motherboards - UEFI, GPT?

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UEFI, GPT?

Printed From: ASRock.com
Category: Technical Support
Forum Name: Intel Motherboards
Forum Description: Question about ASRock Intel Motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=10116
Printed Date: 07 Aug 2025 at 3:56am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com

Topic: UEFI, GPT?

Posted By: TomBm
Subject: UEFI, GPT?
Date Posted: 10 Nov 2018 at 2:09am

" rel="nofollow -

I was planning to upgrade from 500GB hard drive to 3TB hard drive. I tried to clone Win10 installation and partitions from old drive to new one but it resulted in unbootable drive because new drive was formatted as GPT drive. Another method cloned drive using MBR only but about 700GB remains unallocated and can't be used due to 2TB limitation of MBR.

To my understanding some kind of UEFI setting should be enabled to allow booting from GPT drive but I can't find such setting in my UEFI BIOS of Asrock P67 Pro mainboard. Also Win10 system information shows BIOS as "legacy". Doesn't my MB support UEFI even if it does have UEFI BIOS or should it detect GPT drives automatically? Or is fresh installation of Win10 on new drive the only way?

Replies:

Posted By: RLGL
Date Posted: 10 Nov 2018 at 10:22pm

" rel="nofollow - What happens with a fresh install?

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Asrock Z370 Gaming K6,Intel i7 8700K,
Asrock x570 Taichi

Posted By: TomBm
Date Posted: 10 Nov 2018 at 11:20pm

I just wanted to avoid the pain of reinstalling everything, altough I think it would have been easier than trying to clone old disk number of times before finally getting it right. So I managed to transfer OS from old MBR disk to new GPT drive successfully and even got it to boot. Apparently it was necessary to

1) create 250MB EFI-partition to new GPT drive first before anything using diskpart

2) then clone old partitions after that

3) and finally boot into command prompt using Win10 recovery USB thumb drive and add+fix bootloader on new GPT disk.

There was also CSM-setting in BIOS that I disabled but I don't know if it was necessary. Apparently it enables support for old MBR stuff so I don't need it anyway anymore.