Convert your boot drive from MBR to GPT for UEFI

[SansVarnic]

The method I am providing comes from this source: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

This is not my work so please note this.

This topic will be pinned to help to reduce the number of topics asking this question (hopefully).

I have used it on my m.2 drive with no issues, it went flawless and took about 2-3 minutes to execute.

 

Checking MBR or GPT partition style

Quote

Before modifying your system configuration, we recommend checking your current settings to see if the system is set to MBR or GPT using these steps:

1. Open Start.
2. Search for Disk Management and click the top result to open the experience.

3. Right-click the drive (where Windows 10 is installed) and select the Properties option.

4. Click on the Volumes tab.

5. Under the "Partition style" field, if the field reads GUID Partition Table (GPT), the drive doesn't need conversion, but if you see the Master Boot Record (MBR) label, you can use the conversion tool to switch.

6. Click the Cancel button.

Once you complete these steps, you'll know if it's necessary to change the partition style on your device.

Also, if you need to change the partition, make sure to check your device manufacturer's support website to find out if the hardware includes support for UEFI before using these instructions.

 

Converting MBR to GPT partition style (recommended)

Quote

To convert a drive using MBR to GPT on Windows 10, use these steps:

1. Open Settings.
2. Click on Update & Security.
3. Click on Recovery.

4. Under the "Advanced startup" section, click the Restart now button.

5. Click the Troubleshoot option.

6. Click on Advanced options.

7. Click the Command Prompt option.

8. Select your administrator account and sign in with your credentials (if applicable).

9. Type the following command to validate that the drive meets the requirements and press Enter:

   mbr2gpt /validate

   Quick tip: The mbr2gpt.exe is located in the "System32" folder inside the "Windows" folder. If you want to see all the available options, you can use the mbr2gpt /? command.

10. Type the following command to convert the drive from MBR to GPT and press Enter:

    mbr2gpt /convert

11. Click the Close button in the top-right corner of the console.
12. Click the Turn off your PC option.

After you complete the steps, several actions will take place, including validation of the drive and creation of an EFI system partition (ESP). The UEFI boot files and GPT components will be added to the partition. Then the MBR2GPT tool will update the Boot Configuration Data (BCD), and the previous letter will be added to the drive.

 

I hope this helps anyone looking to do this on their own in preparation for Windows 11.

I did this a while back only to enable UEFI on my Windows 10 rig. Not to prepare for Windows 11, my machine is too old and doesn't meet the system pre-requisite anyhow (No TPM Module installed).

[throwaway3224]

Risk when changing BIOS to UEFI or CSM=Disabled:

 

NVIDIA 10-series and earlier GPUs can end up with no display output with CSM disabled/UEFI boot enabled. 
This is because the outputs are prioritized DVI->HDMI->DP.
For example if you use DP and lose display output you can plug in an HDMI monitor to recover.
Then you can install DisplayPort firmware update from NVIDIA.
NVIDIA Link: https://www.nvidia.com/en-us/drivers/nv-uefi-update-x64/
Discussion: https://linustechtips.com/topic/663941-post-screenbios-doesnt-display-with-displayport/
I've seen AMD GPU users report the same issue, but don't know the fix for them.

 

[SansVarnic]

7 hours ago, throwaway3224 said:

Risk when changing BIOS to UEFI or CSM=Disabled:

 

NVIDIA 10-series and earlier GPUs can end up with no display output with CSM disabled/UEFI boot enabled. 
This is because the outputs are prioritized DVI->HDMI->DP.
For example if you use DP and lose display output you can plug in an HDMI monitor to recover.
Then you can install DisplayPort firmware update from NVIDIA.
NVIDIA Link: https://www.nvidia.com/en-us/drivers/nv-uefi-update-x64/
Discussion: https://linustechtips.com/topic/663941-post-screenbios-doesnt-display-with-displayport/
I've seen AMD GPU users report the same issue, but don't know the fix for them.

 

Set your CSM to AUTO, this "should" fix that. It allows the Secure Boot/UEFI to occur properly and any drivers that need/require the legacy will still load in most cases it will load priority to the UEFI then any legacy drivers if UEFI fail to load.

I cannot say with 100% certainty though as each mobo and bios is different.

I use a 1080 [non-Ti] gpu and primarily a DP output to 3 daisy chained monitors and have not experienced this issue with my conversion, not saying it cannot happen of course.

[Folktale]

I have few questions regarding this:

 

1. The process is same for a non-partitioned SSD?

2. So, first, one needs to convert the boot drive or all other drive to GPT, and then enable UEFI option in the BIOS?

3. If one has multiple drives, do they all need to be converted to GPT or just the boot drive?

4. One needs to have these two options enabled or just present for Windows 11 to work?

[Thaelin]

My prep for win11 was to sit back and see what was said about it.  I was a beta tester 3 times and found them useless in all but a few areas. I sadly did grow up in the Unix world and found windows a wannabe imposter. I still use Unix/Linux and will most likely always do so. Win is just too unstable for me as I have one machine that has now passed the 2yr without a reboot mode.

[SansVarnic]

On 7/21/2021 at 11:31 AM, Folktale said:

I have few questions regarding this:

 

1. The process is same for a non-partitioned SSD?

2. So, first, one needs to convert the boot drive or all other drive to GPT, and then enable UEFI option in the BIOS?

3. If one has multiple drives, do they all need to be converted to GPT or just the boot drive?

4. One needs to have these two options enabled or just present for Windows 11 to work?

Apologies for the extremely late reply....

1. Yes

2&3. The Boot drive is the only one you need to convert, but you can convert them all if you want to. When you can [should] set the bios after the conversion.

4. The drive needs to be converted and the bios set to option for 11 to accept it for install.

On 8/30/2021 at 12:28 AM, Thaelin said:

My prep for win11 was to sit back and see what was said about it.  I was a beta tester 3 times and found them useless in all but a few areas. I sadly did grow up in the Unix world and found windows a wannabe imposter. I still use Unix/Linux and will most likely always do so. Win is just too unstable for me as I have one machine that has now passed the 2yr without a reboot mode.

Ok but what is your point you want add that is contributing to this topic?  I see no relevance with this reply.

[aramini]

From the source article link by OP:

 

Quote

Unlike previous methods that required to you to back up your data and perform a reinstallation of Windows, the MBR2GPT command line streamlines the process to change partition styles in minutes.

Yeah, right. I don't trust that. I attempted to convert my MBR to GPT using this method and my boot loader got hosed. Went through the process of recovery, fixing the boot loader, etc. No luck Windows would not boot.

 

I ended up having to clone my Windows partitions as a backup, wipe everything and start fresh starting out with a GPT partition, clean installing Windows, all the settings, configuration, etc, and then migrating my data back from the  clone manually.

 

During the process of trying to fix Windows boot loader, my RAID1 mirrors got hosed. Something happened to the RAID metadata on the drives (AMD RAID w/RAIDXpert2).

 

Luckily, I was able to recover everything using TestDisk, recreating the arrays and restoring the data from recovery/backups.

 

It doesn't take that long to backup/clone your OS partition. A few hours of precaution vs the 2 days I spent recovering & rebuilding.

 

I don't care what M$ or anyone else says, always backup, clone or image your drives before messing with partitions, partition tables, etc.

 

I am not a n00b and have lots of experience. Being impatient/lazy bit me in the arse. I knew better than to trust a Windows tool like that.

 

Be warned. Good luck!

[_Grid21]

On 6/26/2021 at 9:01 PM, SansVarnic said:

The method I am providing comes from this source: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

This is not my work so please note this.

This topic will be pinned for a limited time to help reduce the number of topics asking this question (hopefully).

I have used it on my m.2 drive with no issues, went flawless and took about 2-3 minutes to execute.

 

Checking MBR or GPT partition style

 

Converting MBR to GPT partition style (recommended)

 

I hope this helps anyone looking to do this on their own in preparation for Windows 11.

I did this a while back only to enable UEFI on my Windows 10 rig. Not to prepare for Windows 11, my machine is too old and doesn't meet the system pre-requisite anyhow (No TPM Module installed).

I have an issue where windows says in the convert process "Cannot find room for EFI system partition" "MBR2GPT: Converstion fail" and I don't know how to fix this and I need help. 

[Per Sorensen]

I also had a problem using MBR2GPT.

 

I managed to fix it by running SFC /scannow on the SSD as Admin in a CMD prompt..

 

That fix it, so I could convert a 500 GB SSD from MBR to GPT (while still running Windows 10 Pro Retail) on a AM4 Ryzen 3 3200G and a Radeon WX2100 Workstation / CAD GPU.

 

Hope this help You..

[camelpolo]

Hello,

 

I've tried following the steps to convert, but I'm having a hard time validating the partitions. It seems like the recovery and reserved have split during my last install. I'm not very good at these, I can usually get my way through it - but I was curious if you have any advice on how to validate the drives.

 

Thanks,

 

 

[ho72]

I recently converted my OS disk from MBR>GPT for the purpose of moving it to new hardware. I largely followed the steps given here. This involves using Macrium Reflect (provides easy access to WinPE) and although I have the paid version I think this can be done with the free version as well. Note that redeploy to new hardware is not in the free version, but these days Windows doesn't really require it anyway. I was able to complete the job without it.

[SansVarnic]

My apologies for my late replies. I don't always see the notifications from this topic.

 

On 9/23/2021 at 5:31 PM, aramini said:

Yeah, right. I don't trust that. I attempted to convert my MBR to GPT using this method and my boot loader got hosed. Went through the process of recovery, fixing the boot loader, etc. No luck Windows would not boot.

Always back up your data when performing changes to your drives/system. I should have added this to my op, but this has been widespread practice for some time now, guess I give too much benefit of doubt with this bit of information.

 

On 9/23/2021 at 5:31 PM, aramini said:

I am not a n00b and have lots of experience. Being impatient/lazy bit me in the arse. I knew better than to trust a Windows tool like that.

 

Be warned. Good luck!

Everyone makes mistakes, even the experienced ones. Including me. Glad things turned out well for you.

 

On 10/6/2021 at 10:18 PM, _Grid21 said:

I have an issue where windows says in the convert process "Cannot find room for EFI system partition" "MBR2GPT: Converstion fail" and I don't know how to fix this and I need help. 

Could be a drive error run SFC / scannow  in your command prompt. 

On 11/22/2021 at 5:23 AM, Per Sorensen said:

I also had a problem using MBR2GPT.

 

I managed to fix it by running SFC /scannow on the SSD as Admin in a CMD prompt..

 

That fix it, so I could convert a 500 GB SSD from MBR to GPT (while still running Windows 10 Pro Retail) on a AM4 Ryzen 3 3200G and a Radeon WX2100 Workstation / CAD GPU.

 

Hope this help You..

Make sure you're quoting or motioning the person you are replying to so they get notified of your response.

On 1/19/2022 at 6:34 AM, camelpolo said:

Hello,

 

I've tried following the steps to convert, but I'm having a hard time validating the partitions. It seems like the recovery and reserved have split during my last install. I'm not very good at these, I can usually get my way through it - but I was curious if you have any advice on how to validate the drives.

 

Thanks,

 

 

It's possible you will need to wipe and start over with your drive; this is odd behavior. The validation process should not be creating or splitting partitions like that. Windows will create partitions as needed when it runs its installation.

 

On 2/18/2022 at 9:27 AM, ho72 said:

I recently converted my OS disk from MBR>GPT for the purpose of moving it to new hardware. I largely followed the steps given here. This involves using Macrium Reflect (provides easy access to WinPE) and although I have the paid version I think this can be done with the free version as well. Note that redeploy to new hardware is not in the free version, but these days Windows doesn't really require it anyway. I was able to complete the job without it.

I am not familiar with the method you are using. This topic covers the built-in method provided by Microsoft within windows 10 not 3rd party software.