Windows 11: Change boot logo

It all started with me wanting to change the boot logo of my Windows 11 computer.

The EFI (extensible firmware interface) is a protected, FAT32-drive with a size of 100 mb that usually is invisible to you in the file explorer. You can however see the partition in Disk management which you access as administrator through the program called Computer Management. At the end of the blog post I will show you how you can access it through PowerShell if you are curious. Always treat this partition with great respect.

My research led me to HackBGRT and here you are offered software that temporarily maps your EFI drive so that you can change the boot logo for one of your own.

How to design the logo

The requirement for the logo is that you have a 200 x 200 pixel image in the format of a 24-bit BMP image. It requires the name splash.bmp and that is has a black background if you want to achieve a "transparency effect", since the boot up background on most computers is black. 

In my experience it was better to have an icon that was wide on top of the square background, rather than trying to have a square icon as the image still became stretched out.

Use HackBGRT to change boot logo

1. Download the .zip and extract it in a suitable folder.
   
   
2. Perform a backup of your system through a system restore point, this is because changes in the EFI can destroy your boot up process.
   
   
3. Make sure that you've created the image and placed it in a folder that you remember. You also need Paint installed on your computer.
   
   
4. Run setup.exe in the HackBGRT folder, accept the UAC prompt and then press I to install the logo.
   
   
5. Close the "readme.txt" that pops up, this will now open Paint. Using Paint now go to file and select open.
    
6. Now you should have a file explorer window from Paint open. Navigate to your custom logo location, copy it, navigate to "This PC" and you should find a new A: drive. Navigate to the following: A:\EFI\HackBGRT and then paste the custom logo. You are prompted to replace existing file in destination, confirm to continue.
   
   
7. Close Paint, exit the setup.exe window and then restart your computer to see if it work.

To restore your logo back to the original you run setup.exe and use R instead. 

Access the EFI through PowerShell

First we need to turn the EFI partition into a visible drive so that it becomes easier to work with.

1. Open an elevated PowerShell window (run as administrator)
2. Write Diskpart to activate the Diskpart program within PowerShell
3. With Diskpart now running use the command and write list disk. This displays your available disks. Take note of with number your main disk has, usually 0.
4. In order to target the right disk, write select disk 0 and get confirmation.
5. In order to target the EFI partition we need to identify it. Write list partition and take note of the number, it is labeled as system type and has the size of around 100 mb. In my case it is partition number 1.
6. To target the EFI partition we now write select partition 1 and get confirmation.
7. In order to actually turn it into a visible drive write assign letter=E or another letter that is not in use.
8. Write exit in order to leave the Diskpart program in the command line.

Continue in the elevated PowerShell window in order to navigate to the EFI drive, you can't access it through the file explorer as it is a FAT32 drive and regular access permissions doesn't seem to work there.

1. Now that you know that the E: drive is the EFI you can use it for the following command.
2. Write Set-Location "E:\EFI\" in order to step into that location.
3. Write Get-ChildItem to list which subfolders exists within that location.
4. Continue to explore subfolders using Set-Location and Get-ChildItem or their aliases sl and gci both which are easier to write but not recommended to use in scripts that are shared.
5. Write exit to close the PowerShell window when you are done looking around.