Quick answer: “Windows could not update the computer’s boot configuration. Installation cannot proceed.” almost always means the PC started the installer in a different boot mode from the one the disk is set up for: UEFI with an MBR disk, or legacy BIOS (CSM) with a GPT disk. Restart, open the boot menu and pick the USB entry that starts with UEFI:, turn off CSM/Legacy in the firmware, and let Setup create fresh partitions on an empty GPT disk. Unplug any other drives while you install.
Applies to: clean installs and reinstalls of Windows 11 and Windows 10 from a USB drive or DVD.
In this guide
Why Setup can’t update the boot configuration
At the end of copying files, Setup writes the boot configuration (BCD) and boot files to a system partition. If it can’t, it stops with this message. The usual reasons:
- Boot mode and disk style don’t match. UEFI boots need a GPT disk with an EFI system partition; legacy BIOS boots need an MBR disk with an active partition.
- The system partition is on another drive. With several disks connected, Setup may try to write boot files to an old partition on a second drive.
- Leftover partitions from an earlier install confuse Setup, especially a damaged or tiny EFI partition.
- Firmware settings such as RAID mode or a half-enabled CSM can also get in the way.
Boot the USB in the right mode
Most PCs show two entries for the same USB drive in the one-time boot menu (often F12, F11, F8 or Esc at power-on, depending on the maker): one plain and one starting with UEFI:. Pick the UEFI: entry. Windows 11 requires UEFI, and it’s the right choice for any PC made in the last decade.
To check which mode a working Windows install used, run msinfo32 and look at BIOS Mode: UEFI or Legacy.
Check the firmware settings
- Enter the firmware setup (often F2 or Del at power-on).
- Find CSM, Legacy Support or Boot Mode and set it to UEFI only (CSM disabled).
- If storage is set to RAID or Intel RST and Setup can’t see the disk properly, try AHCI. Don’t change this on a PC that already has a working Windows you want to keep, because it can stop that install from starting.
- Save and exit, then boot the USB again using its UEFI: entry.
Menu names differ by manufacturer. If you can’t find an option, check the PC or motherboard manual.
Disconnect other drives
If the PC has more than one internal drive, unplug every drive except the one you’re installing to (and the USB installer). This forces Setup to put the EFI system partition on the right disk. Reconnect the other drives once Windows starts.
Clean and re-partition the target disk
Warning: these steps erase everything on the selected disk. Back up first, and double-check the disk number.
- On the Setup screen where you choose the language, press Shift + F10 to open Command Prompt.
- Type
diskpart, thenlist disk. Identify the target disk by its size. - Run
select disk 0(use your disk’s number), thenclean, thenconvert gpt. - Type
exittwice, continue Setup and choose Custom: Install Windows only. - Select the Unallocated Space and click Next. Setup creates the EFI, MSR and Windows partitions itself.
Use convert mbr only if you must install in legacy BIOS mode on an old PC that has no UEFI. To keep data on an existing MBR system disk instead, Microsoft’s mbr2gpt tool can convert it in place from a working Windows 10 or 11, but back up first.
Recreate the installation USB
A USB made for the wrong mode boots in only one of them. Create the drive again with Microsoft’s Media Creation Tool (see how to create Windows 10 installation media), or with Rufus, choosing partition scheme GPT and target UEFI (non CSM). If Setup stops at another stage, the steps in how to reinstall Windows 10 may help.
Related guides
- How to make a Windows 10 USB with Rufus
- How to create Windows 10 installation media
- How to reinstall Windows 10
- We couldn’t update the system reserved partition
Official sources: for more detail, see Microsoft’s own pages:
Frequently asked questions
Will turning off CSM break my current Windows?
If that Windows was installed in legacy mode on an MBR disk, it won’t start with CSM off. Since you’re reinstalling anyway, that’s fine; on a working PC, check msinfo32 first.
Do I need Secure Boot for this fix?
No. Secure Boot doesn’t cause this error. Windows 11 expects it to be available, but you can install with it on or off.
Can I fix this without erasing the disk?
Often yes: boot the USB in the mode that matches the disk. If the disk is MBR and you want UEFI, convert it with mbr2gpt from a working Windows, or back up and clean it.
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