CarefulAbout 30 minutesWindows

The installer says the disk has an MBR partition table

Why does my laptop say 'selected disk has an MBR partition table' during install?

CF

Written by The CommonFixes team · fact checked by CommonFixes review desk

Last updated

Short answer

Modern laptops start up in UEFI mode, and that way of starting can only boot from a drive laid out in the newer GPT style. Your drive is still laid out in the older MBR style, usually because it once held an older version of Windows. So the installer stops and tells you the two do not match. You either convert the drive to GPT or tell the machine to start the installer the old way. The quickest thing to try first: decide whether anything on the drive matters — Converting the layout is the clean answer, and one route wipes the drive completely. If there are photos or documents on it, stop now, put the drive in another computer or use a USB adapter, and copy them off first. Do not skip this. Most people are done in about 30 minutes.

Full walkthrough below: 6 steps for Windows, rated careful.

Sounds like this

  • Windows cannot be installed to this disk, the selected disk has an MBR partition table
  • It mentions EFI systems and GPT disks
  • The Next button stays greyed out

Why it happens

Modern laptops start up in UEFI mode, and that way of starting can only boot from a drive laid out in the newer GPT style. Your drive is still laid out in the older MBR style, usually because it once held an older version of Windows. So the installer stops and tells you the two do not match. You either convert the drive to GPT or tell the machine to start the installer the old way.

Work through these in order

0% done
  1. 1

    Decide whether anything on the drive matters

    Converting the layout is the clean answer, and one route wipes the drive completely. If there are photos or documents on it, stop now, put the drive in another computer or use a USB adapter, and copy them off first. Do not skip this.

  2. 2

    Convert without losing data using MBR2GPT

    This works when Windows 10 or 11 is already installed and healthy. At the first installer screen press Shift and F10 to open a command window, run mbr2gpt /validate /disk:0 /allowFullOS, and if it reports validation completed successfully run mbr2gpt /convert /disk:0 /allowFullOS. Microsoft supplies this tool for exactly this job.

  3. 3

    Or wipe and convert with diskpart

    Only if the drive is empty or backed up. Press Shift and F10, type diskpart, then list disk, then select disk 0 using the number of the drive you are installing to, then clean, then convert gpt, then exit. Close the window and press Refresh in the installer. The Next button becomes available.

  4. 4

    Make sure the USB stick itself boots in UEFI mode

    Restart, open the boot menu, usually F12, F9 or Escape depending on the maker, and pick the entry that starts with UEFI followed by your USB stick name. Picking the non UEFI entry is what causes this message on drives that are already GPT.

  5. 5

    Rebuild the USB stick if UEFI is not offered

    Sticks made with older tools are sometimes MBR only. Use Microsoft's Media Creation Tool, or in Rufus set Partition scheme to GPT and Target system to UEFI. A freshly made stick removes a whole afternoon of guessing.

  6. 6

    Check Secure Boot and CSM in the firmware

    Press F2 or Delete during startup to enter setup. Turn off CSM or Legacy support and leave UEFI on. Save and exit. With CSM on, the machine keeps offering the old style boot and the message comes straight back.

If none of that worked

If mbr2gpt refuses with a validation error, it usually means the drive has more than three partitions or the recovery partition is missing. Back up your files and use the diskpart route instead. Never run clean on a drive whose number you have not double checked in list disk, because it erases the entire disk without asking again.

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Who wrote this and how we checked it

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The CommonFixes team

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CommonFixes review desk

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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.

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