Create EFI Partition in Windows 11 (UEFI/GPT): A Complete Step By Step Guide

What Is an EFI System Partition (ESP) in Windows 11?

The EFI System Partition (ESP) is a small part of a hard drive that holds bootloaders and other files that UEFI firmware needs to start operating systems like Windows 11. The firmware on a UEFI-based PC reads boot entries (stored in NVRAM) that point to files on the ESP. These files are usually in folders like: \EFI\Microsoft\Boot\... (Windows Boot Manager files), or sometimes in folders from other vendors (if you dual boot or have OEM tools).

A typical Windows 11 system disk (GPT) has a lot of special partitions, like ESP, MSR, and Recovery. The ESP is the one that is most closely linked to UEFI boot.

When should you make an EFI partition? You might need to make or remake an ESP when:

• You cloned or moved Windows 11 to a new SSD, but it won't start.

• The EFI partition was removed when the partitions were made.

• Windows 11 says "No bootable device" "Boot device not found" or "Can't find Windows Boot Manager."

• You're moving from Legacy BIOS/MBR to UEFI/GPT and need an ESP to start up in UEFI mode.

Important: If your ESP is already healthy, you usually don't need to make a new one. You might just need to rebuild the boot files.

How Big Should the EFI Partition Be for Windows 11? There isn't a single perfect size, but here are practical guidelines:

• Common real-world sizes: 100 MB, 260 MB, 300 MB, 500 MB

• Safe recommendation: 300–500 MB for modern systems and flexibility

• File system: FAT32 (strongly recommended)

If your PC has OEM tools, multiple boot managers, dual boot entries, or you expect changes over time, slightly larger ESP (e.g., 500 MB) can reduce future headaches.

📜 READ MORE:

Windows detected that the EFI system partition was formatted as NTFS. Format the EFI system partition as FAT32, and restart the installation.

UEFI vs Legacy BIOS, GPT vs MBR

Before you create an EFI partition in Windows 11, confirm the boot mode and partition style, because ESP is part of a UEFI + GPT workflow.

UEFI vs. Legacy BIOS

Modern PCs usually start the system using UEFI firmware. In this setup, the firmware looks for boot files stored on the EFI System Partition (ESP) and loads the Windows Boot Manager from there. Everything begins from that small FAT32 partition.

Older systems worked differently. With Legacy BIOS, the startup process depends on code written in the Master Boot Record (MBR) at the beginning of the disk. There's no separate EFI partition involved, and the boot structure is much simpler, though also more limited by today's standards.

GPT vs. MBR

GPT (GUID Partition Table) is the partition style you'll see on most newer PCs. It was introduced as a replacement for the older MBR layout and works naturally with UEFI firmware. One of the reasons it became the standard is flexibility. GPT can handle very large drives and allows many more partitions than older formats ever did. For modern operating systems like Windows 11, it simply fits the environment better.

MBR (Master Boot Record) comes from a much earlier era of PC design. It still works, and you'll occasionally find it on older systems or disks that were set up years ago, but it carries some long-standing limits. The structure only allows a small number of primary partitions, and disk size support is more restricted. Because of that, MBR tends to appear alongside Legacy BIOS setups rather than the newer UEFI approach.

Because of this, most Windows 11 installations today run on UEFI firmware with GPT disks. If your computer is still using Legacy BIOS and an MBR disk, simply creating an EFI partition usually won't fix boot problems. In many cases, the system also needs to be switched to UEFI mode, and the disk may need to be converted from MBR to GPT before the EFI partition can actually be used for booting.

Quick checks (no guesswork)

1. Check BIOS Mode (UEFI or Legacy):

1) Press Win + R, type msinfo32, press Enter

2) Look for BIOS Mode

If it says UEFI, you're on the right track. If it says Legacy, you're not currently booting in UEFI mode.

2. Check disk partition style (GPT or MBR):

1. Open DiskGenius Free Edition.

2. Select the disk you want to check partition table tyle, then view the corresponding item on the right pane:

Before You Start: A List to Help You Keep Your Data Safe

Making an EFI partition is usually safe if you do it right, but it involves changing partitions, which can lead to data loss if you choose the wrong disk or stop operations.

First, use this list:

1. Make backup copies of key files.

Backups are your safety net in case something goes wrong.

2. Check which disk has Windows 11 on it.

A lot of boot failures happen because people make an ESP on the wrong disk.

3. Get ready for unallocated space.

You usually need 260 to 500 MB of free space on the system disk.

4. If BitLocker is turned on, turn it off.

If your system drive is protected, changes to partitions can cause BitLocker recovery.

In Windows, type "Manage BitLocker" into the search box and then click "Suspend protection" (and then click "Resume" later).

5. Have a USB drive with Windows 11 on it ready (recommended)

If Windows won't start, you can get to WinRE (Repair Environment) and use BCDBoot.

6. Don't do this if your battery is low.

The file system can be harmed if the PC loses power while it is running.

Warning: If you don't know for sure which disk is the Windows system disk, stop and check. If you choose the wrong disk in DiskPart or format the wrong partition, you could lose data forever.

Check If You Already Have an EFI Partition (ESP)

Before you create a new EFI partition, confirm whether one already exists.

(1) Using DiskGenius

1. Open DiskGenius Free.

2. Find and expand the system disk (usually HD0)

3. If the system disk is of GPT style, there should be the ESP partition, see the screenshot below:

(2) Using Disk Management

1. Press Win + X → Disk Management

2. Look for a small partition labeled EFI System Partition

Often 100–500 MB

Usually no drive letter

Typically near the beginning of the disk

(3) Using DiskPart (works even in WinRE)

diskpart
list disk
select disk 0
list volume

Look for a volume formatted as FAT32 and typically in the 100–500 MB range.

If you already have an ESP: you may only need to rebuild boot files (BCDBoot), rather than creating a new partition.

An EFI Partition Layout Example for a Typical Windows 11 GPT Disk

On most modern PCs that run Windows 11 in UEFI mode, the system disk isn't just one large partition. Several smaller partitions exist behind the scenes, each with a specific job. Their sizes can vary depending on the device manufacturer or how Windows was installed, but the overall structure tends to look fairly similar.

EFI System Partition (ESP)

Usually around 100–500 MB and formatted as FAT32. This is where the UEFI firmware looks when it needs boot files. Windows stores its boot manager here, typically under \EFI\Microsoft\Boot. You normally won't see a drive letter for this partition in File Explorer, which is intentional. It's meant to stay in the background.

Microsoft Reserved Partition (MSR)

A very small partition, typically 16 MB, and it doesn't show a normal file system. Windows keeps it for internal housekeeping on GPT disks. Most users never interact with it, and in normal situations there's no reason to.

Windows Partition (C:)

This is the main NTFS partition and usually the largest one on the disk. It holds the Windows installation itself along with installed programs, user files, and system data.

Recovery Partition (WinRE)

Often somewhere between 500 MB and about 1 GB. This partition stores the Windows Recovery Environment. When Windows needs to repair itself, reset the system, or troubleshoot startup problems, the tools usually come from here.

A few machines, especially OEM systems, may include additional partitions for factory recovery images or hardware diagnostics. The exact order of partitions can differ slightly, but on most Windows 11 GPT disks you'll still find the same core pieces: an EFI partition, the main Windows partition, and a recovery partition, all working together to keep the system bootable and repairable.

Which Scenario Are You In? (Pick the Right Fix)

Choose the closest match:

Scenario A: A clean install

You're starting again with Windows 11. Let Setup create partitions for you.

Scenario B: Windows is installed, but ESP is not present

You can start Windows or WinRE, but there is no EFI System Partition. To fix this, make an ESP and recompile the boot files.

Scenario C: You copied or moved Windows 11, but it won't start.

Common when switching to a new SSD: make or fix the ESP, rebuild the boot files, and check the UEFI boot entry.

Scenario D: Booting both Windows and Linux

Be careful not to overwrite other bootloaders. Make or fix the ESP on purpose and check the boot entries.

The next parts show you the most common and reliable ways to do things.

When You Should NOT Create a New EFI Partition

Creating a new EFI System Partition is not always the correct fix. In many cases, you can solve boot problems by rebuilding boot files or correcting firmware settings without changing your disk layout.

You should not create a new EFI partition if:

You already have an existing ESP.

If an EFI System Partition is present, the safer approach is often to rebuild Windows boot files on the current ESP using BCDBoot, rather than creating another one.

Your PC is booting in Legacy BIOS mode.

An ESP is designed for UEFI boot. If your system is set to Legacy/CSM mode, creating an ESP alone may not help until you switch to UEFI and (in many cases) use a GPT disk.

You are on a Dynamic Disk / Storage Spaces / certain RAID setups.

Partition operations and boot repair steps can differ. Creating an ESP may fail or introduce unexpected boot issues.

You are dual-booting and your ESP already contains other bootloaders.

Blindly creating or formatting an ESP can break Linux boot entries or OEM tools. Plan carefully and back up first.

You don't have safe unallocated space.

Forcing partition changes without sufficient free space increases risk. Consider resizing properly with a reliable partition manager first.

Method 1: Use DiskGenius to make an EFI partition in Windows 11

DiskGenius is the easiest choice for a lot of people because it clearly shows how your disk is set up and makes it less likely that you'll choose the wrong partition. You can also safely change the size of partitions to make the space you need.

DiskGenius disk map showing the Windows partition, the Recovery partition, and the unallocated space.

Step 1. Launch DiskGenius Free Edition.

Step 2. Locate the unallocated disk space on the system drive, right-click it and choose "Create ESP/MSR Partition".

Tip: If there is not unallocated disk space on the disk, you can shrink a partition to get around 100–500 MB. Here is the guide to shrink a partition without losing data.

Step 3. Select the "Create ESP partition" option and enter the size for the ESP. Then click "OK".

Step 4. Click "Save All" to save the partition to the partition table. Then the program will ask to format the partition. Click "Yes", and the partition will be formatted as FAT32 immediately.

Method 2: Use DiskPart to make an EFI partition and BCDBoot to rebuild the boot files

This way only uses tools that come with Windows. It works on both Windows and WinRE, and it's powerful, but it's also less forgiving because choosing the wrong disk or volume can be dangerous.

When to employ this method:

• You can't (or don't want to) use tools made by other people

• You're using the Windows Recovery Environment

• You want a portable process that runs on commands

Warning: DiskPart does what you tell it to do. Check the numbers and letters on the disks again.

Step 1: Use DiskPart to make the EFI partition

Open Command Prompt as an administrator (or in WinRE, go to Troubleshoot - Advanced options - Command Prompt), and then:

disk part
list disk
choose disk 0
part list
list volume

Check to see if this is the disk that has Windows on it.

You need some free space now. Go ahead if you already have it. If not, Disk Management or DiskGenius is usually easier to use to shrink. (DiskPart can also shrink, but it's more likely to make mistakes.)

Make the EFI partition after you have free space:

make a partition called efi with a size of 300

format quick fs=fat32 with the label "System"

give letter=S

exit

Notes:

• The size is 300 MB. You can use 260, 300, 500, and so on.

• The letter S is a common way to say "System" (you can use any other free letter).

Step 2: Use BCDBoot to rebuild the boot files for Windows 11.

Now do this:

bcdboot C:\Windows /s S: /f UEFI

If Windows isn't on C:, find the right letter first (this is especially important in WinRE, where letters can change):

dir C:\
dir D:\
dir E:\

Then: bcdboot D:\Windows /s S: /f UEFI

Step 3: Take off the drive letter (not required, but recommended)

Step 4: Look at the UEFI boot order

Restart your computer, go to BIOS/UEFI, and make sure Windows Boot Manager is at the top.

Method 3: Let Windows 11 Setup Create the EFI Partition (Clean Install)

Windows Setup is usually the easiest way to do a clean installation.

Steps at a high level:

1. Make a USB drive that can install Windows 11.

2. Start the USB in UEFI mode. You might see something like "UEFI:" in the boot menu.

3. When choosing a disk during installation:

Pick the disk you want to use.

Delete any existing partitions if you want to do a clean install (make a backup first!).

Choose Unallocated Space and then click Next.

Windows Setup will make the necessary partitions on its own, including the ESP.

If you start the installer in Legacy mode, Windows might install in Legacy/MBR mode instead. If you want UEFI/GPT, always use the UEFI boot option for the USB.

Troubleshooting: Common Problems and How to Fix Them

Problem 1: Boot files created successfully but the PC still won't start

Possible reasons:

• The firmware boot order points to the wrong disk.

• The Windows Boot Manager entry isn't the first one.

• You made ESP on the wrong disk (this happens a lot with more than one drive)

How to fix:

Go to BIOS/UEFI and set Windows Boot Manager as the first boot option on the right disk.

Temporarily disconnect non-system disks (this is advanced but works) to find out which disk can actually boot

Problem 2: The BCDBoot error says Failure when trying to copy boot files

Possible reasons:

• The ESP is not in FAT32 format.

• The /s target letter is not right

• Command not run as Admin

• ESP is not available (this is rare, but it can happen if it is not made correctly)

Checklist for fixing:

1. Check the ESP format: Disk Management / DiskGenius → FAT32

2. Make sure that S is really the ESP.

3. Run Command Prompt again as an administrator

4. Give it another shot: bcdboot C:\Windows /s S: /f UEFI

Problem 3: BCDBoot says the requested system device cannot be found

Possible reasons:

• S: isn't the EFI partition

• You gave the wrong volume the drive letter

• The EFI partition wasn't made as an EFI-type partition, which is less common but still possible.

Solution:

• Check the volumes again in DiskPart:

• Check that the S: volume is FAT32 and about 300MB.

• Give letters back to the right people and try BCDBoot again.

Problem 4: BIOS/UEFI doesn't show the Windows Boot Manager option.

Possible reasons:

• The boot entry wasn't made right

• Missing firmware NVRAM entry

• The system is still in Legacy/CSM mode.

Solution:

Check the BIOS Mode:

Run BCDBoot again

Make sure the disk is GPT if you want to boot UEFI.

Problem 5: The BitLocker recovery screen shows up after changes.

Most likely cause: BitLocker finds changes to the boot configuration

Solution:

If you suspended BitLocker before, you should be able to start it up again after a successful boot.

You might need the recovery key if you didn't (this is common in managed or enterprise settings).

Problem 6: You're on MBR and Legacy, but you want to make an EFI partition.

Check the facts:

• Making an ESP doesn't mean that your system will automatically boot into UEFI.

• The disk is usually GPT and the firmware is set to UEFI for real UEFI boot.

Path that works:

Think about changing MBR to GPT (usually with Microsoft's mbr2gpt tool) and then make sure UEFI is turned on.

This is a different step than just making the ESP.

Best Practices (So You Don't Need to Fix Boot Again)

Keep the ESP on the same physical disk as Windows. UEFI boot is most reliable when the boot files live on the OS disk.

Don't assign a drive letter permanently. A visible ESP is easier to accidentally modify.

After cloning/migrating, always verify. Check boot mode (UEFI) and presence of an EFI System Partition.

Avoid multiple "system disks" during installation. When installing Windows, unplug extra drives if possible (prevents Setup from placing ESP on the wrong disk).

For dual boot. Plan ESP usage: either share one ESP carefully or keep a clean structure. Don't delete ESP folders you don't recognize.

FAQs

1. Do I need an EFI partition to run Windows 11?

Yes, if your PC starts up in UEFI mode. Windows needs an EFI System Partition to keep UEFI boot files.

2. Can Windows 11 start up without an EFI partition?

Not in UEFI mode. The firmware won't know how to load Windows Boot Manager if there isn't a valid ESP with Windows boot files in it.

3. Is it possible to make an EFI partition on an MBR disk?

You can technically make a FAT32 partition, but real UEFI/GPT-style ESP booting usually needs GPT partitioning. You might need a conversion plan if you're MBR or Legacy.

4. What kind of file system should the EFI partition use?

For the best UEFI compatibility, FAT32 is the best choice.

5. Can I have more than one EFI partition?

It is possible, especially if you have more than one disk or a dual boot system. But it can also make it hard to choose a boot. Most people should only have one clear ESP on the system disk.

6. Is it okay to give the EFI partition a drive letter?

Yes, but only for a short time to fix the boot (like running BCDBoot). But it's best to take the letter out after that.

7. 5What is the difference between a recovery partition and an EFI partition?

• EFI (ESP): starts the system (UEFI boot files)

• Recovery: keeps Windows recovery tools for fixing or resetting