Windows version 24H2 won't load. Error message says can't update reserve partition

[fraynal01]

I checked the size of the partition and it is at 100MB 100%.  Clearing out the fonts allows 24H2 to progress a bit more.  Furthest it has gotten is 20%.  

Error message is can't update reserve partition.  

[tk_srq]

@fraynal01,

Check the EFI partition to see if it has the HP folder. If it does, it may store the current bios files in the EFI\HP\BIOS\Current folder.  Your bios .bin file should be at least 16 MB, and you can safely remove the .bin file and signature file from the \current folder. This may create enough space for upgrade to W11 24H2, maybe . . . 

See this thread for how to view the contents of the EFI partition in GUI (graphic)mode for easier EFI modification work.

Solved_Delete ESP Files_F.23 BIOS update can't be done due to EFI GPT System Partiti... - HP Support...

[fraynal01]

I have EFI\HP\BIOSUpdate, no .bin files in there.  EFI\HP\ DEVFW has a firmwareupdate.bin at 31MB and Mepending.bin at 9MB. 

[fraynal01]

Any recommendations on how to increase size of EFI partition?  Not sure how I ended up with only 100MB.  

[tk_srq · Accepted solution]

The clean installation of W11 will create the EFI partition that is 100 MB in size by default. The partition holds the \Microsoft and \Boot folders that store boot system files. 

I suppose you clean installed W11 from Microsoft download site. Also, you most likely updated BIOS by running a BIOS update file from inside the Windows or installed HP diagnostics UEFI tool on the EFI partition. Either way, it created the EFI\HP folder that contains the \DEVFW folder and others.

Obviously, you need to remove more files from the EFI partition to create enough space for the update to W11 24H2. 

My suggestion: Remove the \HP\DEVFW folder. Run notepad in CMD and open File Explorer in graphic mode as described in the link in my previous reply. Copy the DEVFW folder to the root directory of C:\ drive and delete the folder. This will free up 40 MB of space which may be enough for the update to 24H2.

Let me know how it goes.

[fraynal01]

Ok that worked.  Now how do I increase size of EFI folder? 

[tk_srq]

This video shows how to increase a size of the EFI system partition (ESP).

How to Increase EFI System Partition Size | Increase System Partition Size

The video shows the Windows partition (C: drive) is shrunk by 1024 MB of space to create a new1 GB ESP, but it doesn't have to be 1024. You can choose 250 MB, 500 MB or any size you want.

If you create a new ESP, you then need to delete the existing 100 MB ESP so that the Windows boots from the new ESP. A third-party partition management software is used to remove the original ESP in the video, but you can do so with command prompt too. If you want to do that, let me know.