Issue with MBR2GPT
Issue with MBR2GPT
HuskyGirl21
11-22-2016, 12:59 PM #1Hello, I'm facing issues transferring my Windows 10 Pro setup from Legacy to UEFI. I'm using a Samsung 970 EVO NVMe M.2 SSD and the installation is installed directly on the motherboard. Windows shows it as Disk 2 instead of Disk 0, which is causing problems. When I tried running mbr2gpt.exe /validate /disk:2 /logs:C:\Windows /allowFullOS from an elevated prompt, it reported validation failure. The logs indicate a layout mismatch—expected one partition but found none. I noticed the OS was in Legacy mode, which made booting into BIOS difficult, and even disabling Fast Boot didn't help. The motherboard model is Gigabyte B450M DS3H. Any advice on next steps? I prefer avoiding a full format and starting fresh.
ThePetrolHit
11-30-2016, 06:33 AM #3Thank you for the update. Disk Management indicates that Disk 2 holds the boot partition and a recovery partition on the drive. I also installed the extra HDDs before setting up Windows on the SSD, yet the boot loader still appears on Disk 2 instead of the expected location. Please let me know if there’s anything else to clarify.
It seems the system likely needs an EFI partition available, which is typical for UEFI setups with three partitions. The issue probably arises because the drive isn’t recognized, so it’s safest to back up important files, remove any connected drives, and securely erase the SSD before reinstalling Windows 10—keeping only the SSD connected to avoid bootloader interference.
stikygamer1
12-09-2016, 02:36 PM #5I realized the System partition is on Disk 0 with Boot and Recovery on Disk 2. Because it failed validation on Disk 0 initially, I think a fresh OS installation is unavoidable. Thanks for the assistance!
IPuckFenguins
12-10-2016, 04:19 PM #6EasyBCD allows you to relocate or generate boot files onto the same partition as the system, including MBR legacy mode. Afterward, mbr2gpt works smoothly without issues.
to Disk 2 (C. After that, MBR2GPT validated the new disk and I successfully completed the UEFI conversion. However, after a restart I encountered a blue screen warning about disk recovery. I powered down the machine, connected a USB with Windows media, but the issue persisted—keyboard and mouse drivers weren’t loaded, leaving me stuck. I realized I had to enter BIOS and disable CSM for UEFI boot. Since my older M.2 still had Windows installed and was already set to UEFI, I adjusted the settings and reinstalled Windows. This whole process began because I needed to enable XMP in BIOS. Short summary: everything worked thanks to your support, and I didn’t have to reinstall Windows again. Thanks once more!
alejandro351
12-14-2016, 04:28 AM #7I just wanted to express my gratitude once more. I followed the guidance in homeap5 and used EasyBCD to transfer the system partition from Disk 0 (G to Disk 2 (C. After that, MBR2GPT validated the new disk and I successfully completed the UEFI conversion. However, after a restart I encountered a blue screen warning about disk recovery. I powered down the machine, connected a USB with Windows media, but the issue persisted—keyboard and mouse drivers weren’t loaded, leaving me stuck. I realized I had to enter BIOS and disable CSM for UEFI boot. Since my older M.2 still had Windows installed and was already set to UEFI, I adjusted the settings and reinstalled Windows. This whole process began because I needed to enable XMP in BIOS. Short summary: everything worked thanks to your support, and I didn’t have to reinstall Windows again. Thanks once more!
Benny_Boy679
12-14-2016, 07:13 AM #8I'm glad you chose a more sophisticated approach instead of reinstalling. It's great to know someone can tackle the issue with minimal guidance, as detailed instructions often aren't necessary.