The Selected Disk is Not a Fixed MBR Disk: How to Fix it

Try fixing the boot manager or converting the disk to MBR

4 min. read

Updated onOctober 4, 2023

updated onOctober 4, 2023

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Key notes

You may come acrossThe selected disk is not a fixed MBR diskerror in Windows 10 when you try to mark a partition on a disk as active on a UEFI System Partition in the Diskpart utility.

BIOS needs an MBR disk type and UEFI needs a GPT disk type, but problems can occur ifMBR is missing. In this guide, we will give you a bunch of fixes that can help fix this error for good.

What causes the selected disk is not a fixed MBR disk error?

After some research, we have found out some of the most common reasons that could triggerThe selected disk is not a fixed MBR diskerror:

How to convert MBR to GPT or vice versa?

We have a dedicated guide that lists some of the best methods that will help you to convertMBR to GPT disk.

You can also check out our guide that lists5+ best disk management toolsthat not only will let you convert disk partitions but also do tasks such as create, resize, rename, delete partitions, and also include PC optimization features.

What can I do when getting the selected disk is not a fixed MBR disk error?

1. Fix Boot Manager

2. Disable UEFI in BIOS

Since GPT is related to UEFI, you should disable UEFI and change the Boot Mode to Legacy. Doing this has resolvedThe selected disk is not a fixed MBR diskerror in Windows 10.

3. Convert Disk to MBR (Using Advanced Recovery Mode)

4. Convert GBT to MBR (Using a third-party tool)

Another freeware solution that can help you convert your MBR hard drive to GPT without file loss is AOMEI Partition Assistant. The application is relatively simple to use, and you can convert your drive by following these steps:

After the process is completed your drive will be converted to GPT. This application won’t delete your files during the conversion so you can use it without fear.

Fixing this problem is easy, but if you have additional issues, visit our guide on how tofix MBR without an installation disc.

That is it from us in this guide. Let us know in the comments below, which one of the above solutions helped you resolveThe selected disk is not a fixed MBR diskerror in Windows 10.

The Selected Disk is Not a Fixed MBR Disk: How to Fix it#

What causes the selected disk is not a fixed MBR disk error?#

How to convert MBR to GPT or vice versa?#

What can I do when getting the selected disk is not a fixed MBR disk error?#

1. Fix Boot Manager#

2. Disable UEFI in BIOS#

3. Convert Disk to MBR (Using Advanced Recovery Mode)#

4. Convert GBT to MBR (Using a third-party tool)#